﻿underblack
table of contents
[Phase 0] The Revealed Secret and the Silent Sister        2
[Phase 1] The humiliation of having one's sexual preferences read aloud and the painful excuses        3
[Phase 2] Shirom's Gaze and His Sister's Portrait        5
[Phase 3] A chilling atmosphere and a sudden proposal        6
[Phase 4] Expanding Fantasies and Hidden Desires        7
[Phase 5] A sweet affirmation that makes you forget reality        8
[Phase 6] The hidden tools and a cruel misunderstanding        9
[Phase 7] Conflicting intentions and sinking consciousness        10
[Phase 8] The Inverted Nightmare        12
[Phase 9] Briefs Observation and the Brutal Reality        14
[Phase 10] The injustice of a reversal and the approaching terror        16
[Phase 11] Flashing Kancho        17
[Phase 12] The lingering echoes of an enema etched into the anus        20
[Phase.13] The anus is exposed as the briefs are cut with scissors.        22
[Phase 14] The compounded prescription and the tip of the rectum        24
[Phase 15] Pleas for surrender and a cold, ruthless line of severance        26
[Phase.16] Glycerin-filled ravages and the ringing of the finale        28
[Phase.17] Not just the pleasure of the first enema.        31
[Phase 18] The resounding melody of the rectum and the stirrings towards criticality        32
[Phase 19] The Limitless 20 Minutes and the Stirring True Feelings        35
[Phase 20] My older sister controls both my ejaculation and bowel movements.        37
[Phase 21] The loop of near misses and confused sphincter muscles        38
[Phase 22] The Two Great Frustrations and the Return of the Glass Edge        41
[Phase.23] Climax and ejaculation after the second enema        43
[Phase 24] The critical point of double filling and the overflowing secret fluid        45
[Phase 25] The bursting brownish stool and the release of hot water        48
[Phase 26] The physiology of the defecation reflex and the intense odor of impacted stool        50
[Phase 27] The remaining feces being squeezed out and a lecture on humiliation        52
[Phase 28] Spontaneous defecation and the final echoes        53
[Phase.29] The Echoes of Violation and Anal Care        56
[Phase.30] Tea party after enema play and unwavering bravado        57
[Phase 0] The Revealed Secret and the Silent Sister
After finishing his boring classes at school, Shirom returned home with heavy steps.
I took off my shoes at the entrance and headed straight to my room, as usual.
I reached for the doorknob and, as usual, turned it.
The door creaked open with a faint sound.
There should have been an ordinary scene there.
However, an unbelievable sight unfolded in the center of the room.
"...Heim?"
I involuntarily uttered that name.
Sitting on the edge of the bed was Heim, the twin sister.
She remains in her school uniform, her eyes quietly closed.
I'm neither angry nor laughing.
However, he maintained an eerie silence, as if deep in thought.
Then, Shirom's gaze was drawn to her feet.
There, piled high like a mountain, were the "suspicious books and games" that were supposed to be carefully hidden to prevent them from being found.
I could feel all the blood drain from my body.
"Why are you in my room?"
His heart began beating like a drum, but Shirom desperately tried to suppress his turmoil.
Panicking at this point would mean completely admitting defeat.
"Welcome back, Shiromu."
Heim slowly opened his closed eyelids.
Those cold, emotionless eyes pierced straight through Shirom.
"I'm not saying 'I'm home.' Could you please stop entering people's rooms without permission?"
Shiromu spoke, trying to appear calm and polite.
My voice almost trembled, but I managed to hold it in.
"yes……"
A short, emotionless voice echoed through the room.
Her gaze shifted from Shirom to the pile of dubious books stacked at her feet.
"It's common courtesy to at least knock, isn't it?"
Shirom refused to admit his own wrongdoing to his sister, maintaining his stance of blaming her for trespassing and continuing to pursue the matter.
I desperately wanted to break this eerie atmosphere.
"Hmm...?"
It was a nod of agreement with an unfathomable resonance, as if searching for something.
I would never press them for an answer.
However, that attitude of simply presenting the facts and waiting to see how the other party would react was more terrifying to Shirom than any angry shout.
"W-what's with that look? Let me tell you, those are my personal belongings. Please don't touch them without permission."
Shiromu continued to speak, as if to further defend himself.
They completely avoided mentioning the questionable content of the book, instead adopting a strategy of solely asserting their claims of infringement of ownership rights and privacy.
"Private matters, huh..."
Heim muttered again briefly, then quickly returned his gaze to Shirom.
His expression remains unchanged.
"That's right. I'm saying please don't touch it without permission. Do you understand?"
Although he spoke a little too quickly, Shirom maintained his resolute demeanor throughout his speech.
I felt a cold sweat running down my back as I waited for my sister's reaction.
"That was quite a lot of... private information, wasn't it..."
A single, emotionless word spilled from Heim's lips.
She simply looked down at the piles of dubious books, utterly dispassionate.
"Ah...! Th-that's why...!"
Taken aback by the unexpected angle of the words, Shirom was finally left speechless.
The mask of composure that he had been so desperately trying to maintain was on the verge of crumbling with a loud crash.
"Collecting them and hiding them seems like it would be a lot of work..."
Heim showed no sign of listening to Shirom's explanation, simply stating the facts.
In the quiet room, only an inexplicable tension weighed heavily.


[Phase 1] The humiliation of having one's sexual preferences read aloud and the painful excuses
Heim casually picked up one book from the top of the stack.
After gazing intently at the illustration on the cover, I turned the page without hesitation.
The rustling sound of paper rustling eerily vibrated the air in the silent room.
"The cold metal tube was pressed against the girl's defenseless anus. With a squelching sound, as if violently pushing and stretching the mucous membrane, the instrument penetrated deep into her anus."
What Heim spoke was by no means a typical account of a man-woman relationship.
This is an extremely niche passage that focuses entirely on enemas and medical play.
Her flat voice, devoid of any emotional fluctuations, further highlighted the strangeness of the printed words.
"'...As I writhed in agony from the heavy, oppressive feeling of my intestines filling with glycerin, my sphincter muscles eventually reached their limit and relaxed. With a pathetic, smacking sound, I shamelessly excreted feces on the examination table...'"
The graphic descriptions of defecation and the heavy, piercing sensation in the stomach caused by enemas are relentlessly read aloud in Heim's low-key voice.
It was a hellish scene: hearing about my most secret sexual fetish, the one thing I least wanted anyone to know, directly from my twin sister.
"No, stop it, Heim! Don't read it out loud!"
Overwhelmed with shame, Shirom's face instantly turned bright red, as if it were boiling.
The heat reached all the way to the tips of my ears, and I couldn't help but cover my face with both hands and scream.
My mind went completely blank, and any logical thinking had long since vanished from my mind.
"Th-that's why! Well, you see, I want to become a doctor in the future, and that's part of my medical studies for that purpose...!"
Confused to the point where he no longer even knew what he was saying, Shirom rambled on with a stream of nonsensical and pathetic excuses.
This is a completely flawed argument that anyone can see is based solely on forcibly extracting the word "doctor" from descriptions of medical role-playing and enemas.
Even so, I desperately wanted to avoid admitting my own fault.
"yes……"
Heim closed the book in his hands with a bang, finally stopping his merciless reading.
Then, she slowly rose from the bed and stared intently at her younger brother, whose face was bright red and who was visibly flustered.
The older twin sister.
Since their heights are almost the same (the fact that Heim is only 1cm taller is annoying to Shirom), their gazes go straight through each other.
Unable to bear it any longer, Shirom averted his gaze and continued making excuses.
"It's purely out of academic curiosity. There are absolutely no ulterior motives. Do you understand?"
His heart was pounding so hard it felt like it would burst, but Shirom somehow managed to maintain a polite tone as he squeezed out words to continue his defense.
There was an instinctive fear that if she showed even the slightest weakness, she didn't know what this mysterious older sister might do to her.
"Shirom wants to become a doctor. Hmm...?"
Heim tilted his head slightly and directed a deep, cold gaze at Shirom, as if peering into the very depths of his soul.
That single, brief nod of agreement was filled with absolute confidence and an air of intimidation, as if he could see right through his younger brother's childish lies.
Shiromu couldn't stop the cold sweat from running down his back, and all he could do was stand there frozen in place.


[Phase 2] Shirom's Gaze and His Sister's Portrait
Shiromu desperately tried to regulate his breathing, his chest rising and falling as he glared at his twin sister, Heim, who stood before him.
They were born on the same day, are the same age, grew up in the same family, and share the same genes—they are truly twins.
However, Shirom always felt that the inner world of that person was nothing like his own, shrouded in an unfathomable grayness.
Heim is a quiet girl who rarely shows her emotions and has a low-key demeanor.
At school, she belongs to the art club, and apparently, she spends her time quietly drawing only black and white monochrome pictures in a dimly lit corner of the clubroom.
Her mysterious aura, which makes it hard to tell what she's thinking, seems to appeal to some boys, but to Shirom, who knows her at home, it's nothing more than an "eerie silence."
At home, Heim was incredibly good at making himself invisible, almost as if he were invisible, and it was a daily occurrence to suddenly find him standing behind you.
On top of that, his intuition is frighteningly sharp, and if Shirom is hiding something, he gives him a look that seems to sense everything without him having to say a word.
Shirom had always harbored a strong aversion to Heim and an irresistible fear of him.
If she had been the type to brandish her authority as an older sister and yell at me, I might have still had room to talk back and argue back.
But Heim was different.
They never raise their voice, but simply observe quietly, patiently waiting for their opponent to self-destruct, slowly cornering them mentally.
That's why Shirom always makes sure to maintain a perfectly logical and polite demeanor in front of her, desperately putting on a brave face to try and seize even a little bit of control.
Even at this very moment, that defense was on the verge of being shattered in an instant, but Shirom absolutely refused to accept defeat against his sister.


[Phase 3] A chilling atmosphere and a sudden proposal
For just a moment, Shiromu was lost in a sea of ​​thought, consumed by a deep and unfathomable fear and aversion to his sister. But a faint rustling sound of paper breaking the silence of the room abruptly pulled him back to reality.
When I turned my gaze back to the front, Heim was aimlessly tracing the cover of the book he had just closed with his fingertips.
Behind her cold, indifferent expression, her sharp eyes were clearly peeking at the lewd words emblazoned on the book's dust jacket.
Apparently, even for the eccentric older sister who usually only draws monochrome pictures, the unusual objects found in her brother's room piqued her curiosity to some extent.
"Hey, Shiromu."
"W-what is it...?"
Heim, still clutching the book, spoke in a low, emotionless voice, almost like a murmur.
His gaze shifted away from the book and fixed intently on the center of Shirom's face.
"Do you actually want to try the things described in this book?"
The sudden, blunt, and utterly incomprehensible question brought Shirom's thoughts to a complete standstill.
"……picture?"
Completely unable to understand what Heim was saying or the true meaning of his words, Shirom let out a foolish question.
I had fully expected that he would thoroughly refute my earlier, utterly childish, and pathetic excuse of "I want to become a doctor in the future" with logical arguments.
"So I was wondering if he'd actually like to try things like enemas with a girl."
Heim, without showing the slightest hint of embarrassment, calmly and casually, as if asking about the menu for tonight's dinner, repeated the unbelievable words and asked again.
At that moment, Shirom's heart pounded violently, making a loud thumping sound.
A powerful wave of shock, as if all the blood in his body were suddenly rushing backward, overwhelmed him.
Shiromu desperately tried to figure out the intentions of his twin sister, who was sitting in front of him, her expressionless face and inscrutable thoughts.
Why would she ask such an embarrassing question with a straight face?
Is this some kind of malicious trap designed to corner me completely, shatter my pride, and make fun of me?
Or perhaps they're just amused by my unusual sexual preferences and want to play with me like a toy.
The more Shirom thought about it, the less he could decipher the true feelings hidden behind Heim's cold, rude eyes, and a clammy, unpleasant sweat began to seep down his back.
"W-what do you mean...? That has nothing to do with Heim, does it?"
Shiromu desperately tried to keep his voice from trembling, maintaining his usual polite tone, and, driven by a defensive instinct, squeezed out the words to ask again.
It was my best attempt at resistance, determined not to reveal my true feelings any further and allow them to take control.
"There might be a connection."
Heim tilted his head slightly and, without changing his expression, uttered a statement that was both abrupt and decisive.
"Do you want to try that enema play thing with me?"


[Phase 4] Expanding Fantasies and Hidden Desires
The words that came from Heim's mouth mercilessly ignited the fuse of the dark desires that had been smoldering deep within Shirom's heart.
My heart began to beat, thump, thump, much faster and hotter than I had ever experienced before.
He gives the girl an enema with his own hands.
It was a twisted desire deep within Shirom, something he had dreamt of ever since he was a child, something he could never confide in anyone, even if the world turned upside down.
In truth, I desperately wanted to place the instrument against a real girl's soft buttocks and pour the liquid medicine into her anus.
However, there was no way to actually fulfill such insane fantasies, so Shirom simply bought these seemingly bizarre books and indulged in masturbation night after night to artificially satisfy his insatiable desires, somehow managing to maintain his sanity in the process.
"......!"
Is it really okay to fulfill that wish, especially against Heim, her twin sister?
Heim stared at him intently with emotionless eyes and asked, as if it were the most natural thing in the world, "Do you want to do enema play with me?" As he faced Heim, Shirom felt as if all his clothes had been stripped away, and even the very shape of his soul was being completely exposed.
In his mind, a vivid, colorful delusion began to swell at an alarming speed.
What if I were actually in a situation where I had to administer an enema to Heim, who was standing right in front of me?
Heim, having exposed his bare buttocks to his younger brother and given an enema, will likely writhe in agony from an exquisite urge to defecate, just like the other unfortunate characters in this book, and will have no choice but to expel the accumulated feces against his will.
A moment of pure bliss where resistance is not permitted, there is nothing you can do but relax your sphincter muscles.
The feeling of depravity from giving my twin sister, who is always perfect, elusive, and somehow seems to look down on me mentally, an enema with my own hands, causing her to miserably leak feces from her rear end.
The moment Shiromu realized that the feast he had only dreamed of was now being offered to him, a powerful shiver of joy ran down his spine.
Objectively speaking, Heim is a beautiful girl who turns heads wherever she goes.
The sheer weight of the act of inserting the enema nozzle directly into that man's perfectly formed face and the cool, mysterious aura he exuded made Shirom feel dizzy.
[Phase 5] A sweet affirmation that makes you forget reality
Shiromu managed to suppress the violent pounding of his heart and swallowed hard, his throat dry.
If I let myself be intimidated here, I'll never be able to look my sister in the eye again.
He held on at the last moment, and in order to maintain his superiority, he deliberately put on a faint, provocative smile.
"H-Heim really wants to try it, so I could... do an enema for you...?"
It was a desperate attempt at bravado.
Shirom's rational mind was sounding the alarm, telling him that he would either be coldly dismissed with the usual "Aren't you an idiot?" or be teased even more.
However, the response he received far exceeded Shirom's expectations.
"Yeah, I'm interested. I'd like to try it."
From Heim's lips came a voice that was surprisingly clear and unwavering.
Normally, she would have brushed it off with a "Hmm...?", but this time she looked straight at Shirom and accepted his twisted proposal with clear intent.
At that moment, something exploded spectacularly inside Shirom's brain.
The shock of having obtained the perfect answer that suited his own convenience, the answer he had always wanted, left his mind completely blank.
A wave of joy and excitement washed over me all at once, and I could feel every cell in my body trembling with happiness.
The girl administers an enema to Heim's perfect and beautiful buttocks with her own hands, forcing him to defecate.
That event, which had only existed in my imagination, had now crossed the boundary of reality and rolled right into my eyes.
Shiromu felt dizzy with happiness, and his vision seemed to warp and distort.
Is this really reality?
Perhaps it's just a convenient dream I'm having while dozing off in class.
Heim's figure, quietly waiting for his words before him, seemed so surreal that it made Shirom doubt his own existence, yet like a sweet fruit, it drove him mad.
I hope this dream never ends. Not until this enema play is over.


[Phase 6] The hidden tools and a cruel misunderstanding
"Okay, then go ahead and prepare the necessary tools."
Heim slowly rose from the bed, and while looking down at the pile of dubious books, he commanded in a terribly cold voice.
"Huh...? Oh, yes. I understand. Please wait a moment...!"
Shirom replied in a voice that was about to crack, and with trembling hands, headed towards the closet.
There, kept hidden away, is a large, locked box that is usually kept in strict secrecy.
He had, of course, never before given an enema directly to a real girl's buttocks.
However, dreaming of that miraculous moment that might one day arrive, I had already bought all the tools necessary to turn my fantasies into reality.
"Hmm..."
As Heim peered in with a curious expression, Shirom opened the lid of the box and took out the various hidden treasures onto the floor.
"Well, this is something I prepared in advance purely for medical study purposes..."
As Shiromu offered a series of weak excuses, he presented what was certainly not one of those cute, commercially available fig enemas you'd find at a drugstore.
A 500ml bottle of commercial-grade glycerin solution, and a large, clunky glass enema syringe designed for 200ml.
Furthermore, adult diapers designed to absorb everything without fail, and horrifying leather restraints to forcibly fix the victim in an M-shaped leg-spread position, appear one after another.
"You seem really determined to become a doctor..."
Looking down at the array of tools that were far too professional, Heim gave me an icy, emotionless gaze.
However, the corners of her thin lips were slightly turned up, as if in a mocking smile.
"Yes, that's why I think I can handle it efficiently...!"
Unaware of the slightest change in Heim's expression, Shirom's heart was pounding with excitement and anticipation, threatening to burst at any moment.
For the first time in my life, I'll be able to give an enema to a girl, and to the older sister of this beautiful girl no less.
I inserted the thick nozzle of the glass enema syringe into Heim's clean anus and administered a generous amount of glycerin solution, causing him to shamefully leak feces.
Just imagining that decadent scene made Shirom's head boil and he was ecstatic.
However, Shiromu, who was so excited, didn't realize it at this time.
There was a huge misunderstanding between Shirom and Heim, one that was like turning the heavens and the earth upside down.
Earlier, Heim did indeed say, "Do you want to try that enema play thing with me?"
The terrifying trap of subject and predicate.
The subject of the phrase "I want to try it" that she proposed.
So, that means...


[Phase 7] Conflicting intentions and sinking consciousness
Faced with the strangely alluring equipment laid out on the floor, the two decided to sit facing each other across a table to decide on the specifics of their game.
In the tense atmosphere, the delicious tea that Heim had brewed from the kitchen was steaming warmly from both of their mugs.
Grateful for his sister's thoughtful actions, which were so unexpected from her usual demeanor, Shiromu took sip after sip of the fragrant tea to quench his parched throat.
"So, can you explain how to use this tool?"
Heim held a warm mug in both hands and pointed to the restraints on the floor in a low voice.
His gaze remains cold and detached, yet it seems to harbor a certain curiosity for the unknown.
"Yes, I'd be happy to explain. This isn't some cheap device that just ties people up."
Thanks to the tea, Shirom regained some composure and began to speak in a heated tone, as if boasting about the distorted knowledge he had kept hidden within himself.
To make his dream scenario of giving a girl an enema perfect, Shirom had been simulating the use of these items in his mind countless times ever since he started collecting them.
"This leather belt securely fastens the recipient's right ankle and right wrist, and another belt similarly fastens their left ankle and left wrist. When this is put on, the person's body is physically fixed in a forced M-shaped leg-spread position. The buttocks and anus are completely exposed and vulnerable. No matter how embarrassed they become and try to struggle, they absolutely cannot escape."
Shiromu seemed unable to contain his excitement, and he spoke passionately, using gestures and body language.
Just imagining Heim's beautiful body completely exposed by the restraints, her genitals and buttocks thrust out in a gruesome state, sent a thrilling shiver down his spine.
"I see... You connect the right to the right, and the left to the left, to make the buttocks completely exposed."
Heim quietly took a sip of tea and nodded slightly, as if in understanding.
There was no fear or shame on his face; he seemed to be calmly processing Shirom's explanation in his mind.
"That's right. And the most important thing is how to prepare this 200ml glass enema syringe and the 500ml glycerin solution. Since this is your first time playing, don't you think it would be a shame to just use some insignificant store-bought enema? I'd like to make this momentous 'enema virginity' a spectacular one with this exquisite 200ml, 30% concentration formula."
Shirom continued to passionately explain his ideal, perfect blend.
This was the ultimate enema theory he had arrived at after devouring countless dubious books.
"A 30 percent concentration is certainly a little weaker than commercially available fig enemas, which are 50 percent... But, in return, if the total amount administered via enema reaches 200 milliliters, the total amount of pure glycerin delivered into the body reaches 60 milliliters. I read in a book that this exquisite 30 percent concentration is what prevents it from over-stimulating the intestinal wall and causing stomach pain. And yet, with an overwhelming amount of 200 milliliters of liquid, it creates an unbearable, intense urge to defecate in the rectum. In other words, it's a formula that doesn't cause pain, but simply lets you experience an overwhelming urge to defecate to the fullest extent. Isn't that wonderful?"
Shiromu rattled off his thoughts in one breath, then, as if intoxicated by his own wonderful plan, he gulped down his tea once more.
My cheeky older sister, Heim, without suffering any stomach pain, simply winced in unbearable urge to defecate and let out a huge load of poop right in front of me.
The conviction that such a dreamlike ending was within his grasp drove Shirom even more mad.
"Hmm... You don't get a stomach ache, but you have a really strong urge to go to the bathroom. You must have studied well."
Heim placed his mug on the table and said quietly, with an admiring tone.
Shirom was completely unaware that a sinister light was quietly flickering in the depths of those eyes.
"Of course. This is a basic courtesy. Now that that's settled, let's get started with the preparations..."
Shirom stood up and began to prepare the enema solution.
However, at that moment, my vision suddenly became distorted and warped.
"...Huh?"
For some reason, I've been feeling like I'm about to lose consciousness.
My head suddenly felt heavy, and my thoughts became completely disorganized, as if it were filled with lead.
A sudden wave of exhaustion washed over me from the core of my body, and my consciousness began to cloud over to the point where it was difficult even to maintain my prideful, polite tone of voice.
"Shirom? Are you okay?"
Heim's voice sounded distant and muffled, as if it were coming from the bottom of a deep body of water.
"W-well, for some reason... my head suddenly feels..."
Shirom tried to put his hands on his desk, but his arms, whose sense of balance was fading, swung through empty air, and his upper body collapsed onto the carpeted floor.
The delicious tea that Heim brewed for me.
Shirom's increasingly dulled brain never managed to grasp what was hidden behind that sweet fragrance.
As his vision rapidly faded into darkness, the last thing Shirom saw was Heim's cold eyes, staring down at him.
With no way to resist, Shirom's consciousness completely plummeted into the depths of darkness.


[Phase 8] The Inverted Nightmare
Shirom was having a very warm dream.
These are fragments of childhood memories from a time when I was much smaller and the world was simpler.
In the park's sandbox at dusk, Heim and I sat side by side, building a large sandcastle with our muddy hands.
The light of the setting sun paints the world in an orange hue.
Heim, standing beside him, gazed at Shirom with the same calm eyes as before, gently brushing the mud off Shirom with his small hands.
There was nothing to fear; only a feeling of pure contentment flowed through that time.
Wrapped in a comforting warmth, Shirom wished he could linger in the afterglow of that blissful dream forever.
However, that tranquil evening scene gradually begins to crumble, as if cracking from beneath your feet.
The air, which had been warm, rapidly lost its heat, and in its place, a strange chill and a stinging, unsettling sensation crept up to the surface of Shirom's consciousness.
The boundaries between dreams and reality become blurred, and the sense of reality slowly emerges from the depths of deep sleep.
Just before fully waking up, in the hazy darkness, Shirom began to grasp the abnormal situation his body was in solely through his sense of touch.
The first thing I noticed was the soft feel of the sheet against my back.
The softness of the fabric was familiar, just like lying on the futon in my own room.
But my own body lying on top of it felt incredibly precarious.
With his upper body exposed and his lower body stripped of his pants, leaving him in just a pair of thin underwear, the unsettling sense of liberation was vividly conveyed by the air of the room directly touching his skin.
And what was strangest of all was the fact that the use of my limbs had been completely taken away.
The moment Shirom tried to move his arm to do something, a hard, cold sensation that seemed to dig into his wrist resisted him intensely, preventing him from moving.
It was the feel of a leather belt that firmly connected my right wrist to my right ankle on the same side.
Furthermore, his left wrist and left ankle were also tied to something equally sturdy.
If you try to extend your arms, your legs are pulled, and if you try to extend your legs, your arms are fixed in place.
Because of its structure, Shirom's body was completely fixed on the futon in a defenseless position with his legs spread wide apart—that is, in a forced M-shaped leg spread—against his will.
I don't understand what's happening, and my thoughts remain incredibly dull, as if shrouded in a fog.
Why am I tied up in such an embarrassing outfit, wearing only my underwear?
The memory of happily drinking tea with Heim just moments ago is floating around in my mind like scattered puzzle pieces.
Shiromu slowly and hesitantly began to open his eyelids, which felt as heavy as lead, while scolding his body that was showing signs of rejection.
A faint light first shines through the slightly opened field of vision.
The familiar ceiling of my own room gradually became clearer as it was projected onto the screen.
Then, blocking that view, the shadow of a figure looking down on you from above appears in the center of the distorted world.
"Good morning, Shiromu."
The voice that came down from above was my sister's, completely unchanged, in a monotone and low-pitched tone.
The moment he heard that greeting, an electric current ran through Shirom's brain, and all his memories and sensations instantly connected into one.
What kind of outfit am I being made to wear right now?
With his hands and feet tied together, right to right, and left to left, and his buttocks thrust out in such a miserable position, what kind of device is being used to put him in this position?
It was none other than the very same restraint device that forced Heim into an M-shaped leg spread, which he had proudly pulled out of the closet in an exuberant mood, and whose mechanism he had so emphatically explained to him.
Shiromu instantly became fully awake, and the shock of terror and humiliation, which made the blood in his body rush back up, left him frozen in place with only his eyes wide open.


[Phase 9] Briefs Observation and the Brutal Reality
Shiromu's breathing became ragged, and he twisted his body violently, desperately shouting in an attempt to deny the sight before him.
"W-what does this mean?! What are you going to do to me?!"
However, Heim paid no attention to Shirom's desperate questioning, looking down at him with cold eyes as if he were gazing at a roadside stone.
"Wow... Shirom still wears briefs?"
Ignoring Shirom's embarrassment, she muttered in a calm, almost utterly exasperated tone.
"Ah...! Th-that's because... it's functional and easy to move in! I-it's not like it's childish or anything like that...!"
Shirom's face turned bright red, and he desperately rattled off a string of excuses.
The mere fact that my beloved, worn-out briefs are being subjected to Heim's cold, ruthless gaze is enough to make my brain burn out with humiliation.
"Hmm...?"
Even after listening to Shirom's pathetic explanation, Heim only responded with a dismissive nod of laughter.
"And even though it's small, it's pitching a tent..."
"...Wha...?!?!?!?!?"
I only realized it after you pointed it out.
Shirom had an erection. His small penis was pointing straight up into his briefs.
"Is that what you call a morning erection...?"
This is a natural physiological phenomenon that occurs in healthy boys, where the penis becomes erect during sleep, unrelated to sexual stimulation or dreams.
"Th-this is something that happens to anyone who sleeps, not just me...!"
"Yeah. I saw the moment when Shirom was sleeping, the bulge in his briefs suddenly tensed up, and I even recorded it."
"W-What are you thinking, recording this, you perverted sister...!!"
Shirom's face turned bright red with shame, and he thrashed his arms and legs, which were bound by restraints, as he desperately retorted in a raised voice.
"Nothing in particular. It's just for keeping a record of our doctor-patient role-playing game, and to preserve evidence of Shirom's pathetic morning erection."
Heim, still speaking in his usual monotonous, low-pitched voice, stared back at Shirom's crotch with cold eyes.
The forced M-shaped leg spread exposes Shirom's body in its vulnerable state.
Through the taut fabric of the briefs, the soft contours of the buttocks and the awkward bulge in the center were burned into Heim's vision.
"Hehe, if you look closely...it's quite yellowed. It kind of smells like pee, Shirom."
Heim made a deliberately exaggerated gesture of sniffing the air with his nose, and added insult to injury with a cruelly emotionless tone.
Shiromu's heart felt like it was about to burst with humiliation.
Having the hidden dirt on his underwear, which he thought he had kept clean, pointed out, made him feel as if his pride had been tainted like mud.
But the humiliation didn't end there.
"Oh, there's a brown streak here too. Is that... what you call a 'poop streak'?"
Heim unceremoniously pointed with his fingertip to the old stains that had seeped into the fabric of his briefs.
Shirom felt all the blood drain from his body, and then he was overcome by a boiling heat.
My most insignificant flaw, the one I wanted to hide the most, is being thoroughly trampled upon by my sister, an absolute presence, and from the angle I least wanted her to see it.
A mix of shame, self-loathing, and an overwhelming sense of inferiority towards her sister caused tears of unbearable humiliation to well up in Shirom's eyes.
"S-stop...don't look...!"
He pleaded in a hoarse voice, but Heim only deepened his cold smile.
"More importantly, what does this mean?! Right now I'm going to give Heim an enema... I'm going to pour plenty of glycerin into Heim's ass..."
Still confused, Shirom clung to him, trying to reaffirm his original purpose.
However, Heim interrupted him with a cold, cruel remark.
"...Aren't you misunderstanding something?"
"picture……?"
Shirom's thoughts came to a halt.
"W-what do you mean, Heim? That's not what we agreed on."
Shiromu's vision wavered with fear.
Heim peered into Shirom's face, which was restrained, and in a cold, emotionless voice, he spoke, shattering his brother's illusions.
"Who said Shirom was going to get an enema? ...All I said was, 'Do you want to try that enema play thing with me?' I mean, I'm going to use all those tools to give Shirom an enema right now."
The moment Shirom understood the meaning of Heim's words, a chilling shiver ran down his spine.
My sister is using my plan against me, trying to manipulate me and use me as a guinea pig.
His cold, calculating smile told the whole story: he had seen through Shirom's misunderstandings a long time ago.


[Phase 10] The injustice of a reversal and the approaching terror
The utterly heartless announcement of the enema that came from Heim's mouth completely exceeded Shirom's brain's processing capabilities.
I will be the guinea pig, the one receiving the enema.
The moment Shirom tried to comprehend that fact, his mind was thrown into a chaotic mess of intense confusion and furious anxiety.
"Huh...? Uh, wait a minute! What are you talking about, Heim!"
With his hands and feet bound in restraints, Shirom writhed desperately like a fish caught in a net, screaming like a madman.
Because his right wrist and ankle, and his left wrist and ankle, were tightly bound, the more he thrashed about, the more his buttocks and anus, encased in only thin briefs, were thrust out in front of Heim's eyes in a large, gruesome manner.
The sheer shame and injustice of the situation made Shirom's heart pound frantically, and cold sweat poured from his entire body like a waterfall.
In the first place, according to Shirom's preconceived notions, enema play was without exception something that "men did to girls."
In fact, whether it was the numerous "indecent books" he carefully hid in the back of his closet, or the lewd world of games he kept hidden behind his computer, it was always the lovely, beautiful girls who were forcibly restrained, had instruments inserted into their anuses, and were made to cry out and defecate.
The idea that he, a boy, could be the one being attacked and the weaker party had never even crossed Shirom's mind up until that point in his life.
"Why... why do I have to go through something like that?! It's ridiculous!"
Desperate to prevent his pride from collapsing, Shirom glared intensely at Heim with teary eyes and somehow managed to force out his usual polite tone as he protested fiercely.
His pride as a man, and the sense of superiority he had maintained over his sister, were now on the verge of being shattered into a million pieces in the face of this humiliating M-shaped leg-spread position.
The dream tool that allowed me to subdue girls and make them defecate from their asses turned out to be nothing short of a nightmare, transforming into a weapon to tie myself up and violate my own anus.
"There's nothing strange about it... After all, Shirom said it himself, didn't he? 'For this momentous first play, I want to disperse it with a superb formula of 200 milliliters at a concentration of 30 percent.'"
Heim, with a cold gaze, watched Shiromu's distressed state and, without losing the slightest hint of his low-key demeanor, calmly picked up the enormous glass enema device that had fallen to the floor.
Her slender, beautiful fingertips touch the cold glass tube of a crude medical instrument.
Her expression showed neither anger nor excitement, but only a chillingly cold curiosity, a quiet sting of the unknown experiment that was about to begin.
"Th-that was meant for Heim, not to mean that you should take away my enema virginity...! Stop it, don't touch me!"
Shiromu's face contorted with fear, and he desperately tried to close his thighs, but the sturdy leather restraints creaked and dug into his flesh, forcing him into an even more humiliating M-shaped spread.
The roundness of his buttocks, fully exposed through the gap in his briefs, twitched and trembled slightly with fear as it faced the tip of the glass enema syringe held by Heim.


[Phase 11] Flashing Kancho
Shiromu shook his head violently from side to side with tears in his eyes, twisting his waist as if trying to roll over in his sleep and thrashing about.
However, in the M-shaped leg-spread position, with her wrists and ankles tightly bound together on the same side, no matter how much she struggled, her buttocks only bounced uselessly on the futon, and she could never escape from the crucial Heim.
"Don't thrash around so much, Shirom. It's dangerous... If you thrash around like that, that glass enema kit will fall to the floor and break."
Heim lightly shook the large glass enema device in his hand as if handling a dangerous toy, and reprimanded Shirom in his usual cold, monotone, and low-pitched voice.
His gaze slowly moved further downwards from his younger brother's face, which was contorted with fear.
"By the way, Shirom. I took off your clothes while you were sleeping, but do you know why I left these briefs on you?"
Heim stared intently at the yellowed, worn-out fabric of the briefs that tightly hugged the rounded shape of Shirom's buttocks, and asked the question.
"Huh...? W-what for...?"
A new wave of confusion and an ominous premonition began to creep into Shirom's mind.
Perhaps he deliberately exposed himself in his embarrassing briefs to completely shatter his own pride.
"Think about it. If Shirom has studied doctor-patient games well, he should know right away."
Heim tilted his head slightly, pausing as if to give himself time to think.
"Is that... your way of showing consideration as an older sister, to prevent me from catching a cold...?"
Shiromu, clinging to a glimmer of hope, spoke in a polite tone about the most harmless possibility.
However, Heim's reaction was cold.
"Wrong"
It can be dismissed with a short, one-word remark.
"So, then, is it so you can use it as a cushion before putting on a diaper...?"
Shirom's face turned even redder as he answered, anticipating the next embarrassing turn of events.
"That's also wrong."
A dark, almost ominous light gleamed in Heim's eyes, as if he was somehow enjoying his brother's off-target answers.
"I don't understand! Please stop being mean and explain it to me, Heim!"
Unable to bear any more humiliating quizzes, Shirom cried out, his leather restraints creaking loudly.
"You don't know the answer?"
Heim quietly placed the glass enema syringe he was holding onto a nearby table.
"Shall I teach you?"
Immediately after muttering that, Heim brought both hands together in front of his chest, firmly aligning his index and middle fingers, creating an eerie stance like a ninja forming a hand seal.
It was that dreadful hand gesture that Japanese children use as a daily prank.
"A wedgie!!"
At the same time as Heim's sharp cry, the fingertips of both her hands clenched the air with a perfectly aimed strike.
Thud!!
"Huh!?!?!?"
A wordless scream was squeezed out from the back of Shirom's throat.
At first, Shirom's brain couldn't immediately comprehend what had happened to him.
But the next moment, a tremendous sensation, as if the Earth itself had crashed into the center of his buttocks, shot through Shirom's entire body.
A violent vibration runs through the depths of my buttocks, as if a spectacular explosion has occurred from within, and I am overcome by a sensation that shakes me to the core of my skull.
My vision went completely white, and an intense shock, like twinkling stars flying out of my eyes, directly scratched my brain.
The aftershocks continued without end, piercing through the skin of my buttocks and resonating with a heavy, thudding impact, as if I had been punched directly into the deepest part of my abdomen, the wall of my rectum.
It wasn't a sharp "pain" like a cut or a scrape.
It was simply the most overwhelming and destructive shock to my buttocks I had ever experienced in my life.
As his sense of time stretches, Shirom's brain gradually begins to grasp exactly what is happening to his rear end.
Using the worn fabric of his briefs as a medium, Heim's two firm, aligned fingertips mercilessly penetrated his defenseless anus.
The flesh of my buttocks is stretched to its limit with a squelching sound, and an intense pressure ravages the area around my anus.
It was only then that Shirom finally fully understood the fact that he had been subjected to a "kancho" (a prank involving poking someone's anus) by Heim's finger.
"Ah, ha... ahh...! I, I got an enema...!?"
A groan filled with humiliation and shock escaped Shirom's lips.
Having awoke from a state of semi-consciousness, with his legs spread in an M-shape, and completely unsuspecting, the unexpected sensation of this enema hit his anus with many times the normal destructive force.
Because he had let his guard down, the mucous membrane of his anus, which had been relaxed and powerless, was forcibly pushed inward along with his briefs by Heim's fingers, and he was trembling with an intense sensation he had never experienced before.
The mere fact that he had been subjected to a "kancho" (a prank involving poking someone's anus) completely shattered Shirom's dignity as a man.
The intense aftereffects of the enema still swirl around my anus, a burning heat.
"Shirom, you're a boy, but this is your first time getting an enema? Before I take your virginity with a real enema using a chemical solution, I thought I'd take your enema virginity with a finger first... My enema worked really well, didn't it?"
Heim slowly pulled out the fingertip that he had inserted deep into Shirom's anus, making a squelching sound.
Then, he looked down at his younger brother's face, which was sobbing and he had forgotten to breathe, with a low-key but somewhat satisfied expression.
"Now you know the answer to the question from earlier, right?"
Heim stared at his fingertips and calmly explained the reason, as if revealing a secret.
"Sticking a finger into a bare anus isn't a kancho, that's just finger insertion into the anus. A kancho is something like this, forcefully thrusting through clothing. That's why the fabric of those worn-out briefs unexpectedly and powerfully digs into the anus, creating an intense sensation that's not pain, but something indescribable. See, I told you so, Shirom?"
Heim's explanation was the ultimate psychological torment for Shirom.
The briefs I was wearing had been perfectly used by Heim as a weapon to most effectively violate my anus.
Overwhelmed by the shock and the lingering, vivid sensation of the enema, Shirom could only sink into despair, breathing heavily in a spread-legged position.


[Phase 12] The lingering echoes of an enema etched into the anus
The fact that Heim, though his sister, was a genuine girl, had given him a wedgie had shaken Shirom's sanity to its core.
Based on Shirom's previous understanding, he had always thought that the prank of "kancho" (a prank involving poking someone's anus) was something boys did in school hallways or muddy playgrounds as a way to stubbornly argue with each other.
To have that done to me by my beautiful twin sister, who has such perfectly formed features, and in such a perfect, unexpected way, was so humiliating and embarrassing that I felt like I was going crazy.
Heim's tremendous thrusting into Shirom's anus left the thin fabric of his worn-out briefs mercilessly and forcefully embedded deep within the cleft of Shirom's buttocks, right into the delicate mucous membrane of his anus.
The raw, unsettling feeling of his anus being stretched open by a foreign object left Shirom with tears welling up in his eyes, and all he could do was breathe heavily.
"Oh, your briefs are stuck in there. Let me pull them out for you."
Heim, still speaking in his usual emotionless, low-key voice, reached out his slender fingertips once again towards Shirom's defenseless buttocks.
Then, he grabbed the edge of the briefs, which was firmly lodged deep inside his anus, with his fingertips and slid it straight up to pull it off.
As a faint squelching sound echoed as the fabric peeled away from the mucous membrane, a powerful, tingling sensation unlike anything Shirom had ever experienced before ran through the area around his anus.
The frictional sensation of being dragged and the feeling of his skin suddenly being exposed to the air mixed together, creating such an intensely decadent pleasure that Shirom's body twitched violently.
"Ahhh...!? P-please stop, Heim..."
With a pathetic cry, Shirom was terrified by the changes happening inside his body.
Incredibly, the longer it was time since he'd been pricked in the anus, the more the intense heat of that shock spread slowly deep inside his buttocks, melting Shiromu's stubborn heart into a sweet, melting sensation.
That was to be expected.
With the right limbs and left limbs firmly bound together with leather belts, the person is forced into an M-shaped leg spread, completely exposing their anus without any concealment whatsoever—the perfect position for a kancho (a prank involving inserting fingers into someone's anus).
His only defense was a single pair of thin briefs, a truly inadequate outfit.
And then, the surprise attack came at the perfect moment—right after he had woken up from losing consciousness.
These favorable conditions perfectly aligned, and the impact of Heim's fingertips was imprinted on Shirom's immature anal nerves as an overwhelming, brain-melting pleasure.
His anus began to twitch and convulse involuntarily, and in conjunction with this, his small penis, tucked into the front of his briefs, slowly began to heat up and harden, on the verge of becoming erect.
Why are my genitals reacting in such a shameless way when I am merely being subjected to such humiliating torture?
Shirom couldn't help but feel intense anxiety and despair at his own body's betrayal.
"Ah... Just as I thought... The part of the briefs that was pressed against my butt has turned a faint brown..."
Heim stared intently at the stain on the cloth he had pulled out, then shoved it right in front of Shirom's face, calmly provoking him with the fact.
"What...! Ah, uh, you're being noisy! I told you not to look!"
Shiromu's face turned bright red all the way to behind his ears, and he desperately shook his head, trying to avert his gaze.
However, Heim's merciless verbal bullying goes even deeper.
"This definitely smells like poop. It stinks so much, Shirom."
Heim removed his fingers from the fabric of the briefs, then brought the fingertips of both hands that had been directly poking Shirom's anus to his nose and began sniffing without hesitation.
"These pants don't smell like a boy's, they smell completely like poop. Shirom, are you constipated or something?"
When his twin sister pointed out directly that the smell of feces had transferred from her own anus, Shirom's dignity was completely reduced to ashes.
The ultimate humiliation: in front of Heim, who is perfect, cool, and looks down on me, I have streaks of poop on my pee-smelling briefs, and the smell even lingers on my fingers.
Shirom could only tremble uncontrollably in his bound position, tears streaming from his bright red face, terrified of the enema play that was about to begin.


[Phase.13] The anus is exposed as the briefs are cut with scissors.
The lingering, intense sensation of the enema deep inside his buttocks, combined with the ultimate humiliation of having the smell of feces transferred from his fingertips pointed out, left Shirom's mind completely exhausted.
However, Heim's ruthless and cold control showed no sign of easing even slightly.
"Well then... That's the end of the surprise anal pokes through clothes, so these briefs are no longer needed."
Heim took a particularly large, sharp-looking pair of craft scissors from a drawer in a nearby study desk and returned to the bedside, making a small, crisp metallic click.
"W-what...what are you planning to do, Heim! Where are you pointing those scissors?!"
Shiromu's eyes widened in terror, and he thrashed his arms and legs, which were bound by restraints, desperately, but each time he moved, the leather belts only dug harder into his flesh.
"Well... this restraint device that Shirom procured himself is excellent because it firmly fixes the right side to the right and the left side to the left, forcing him into an M-shaped leg-spread position. Because of that, it's physically impossible to pull his briefs down and take them off normally while his buttocks are fully spread open... So, the only way is to cut them open with scissors like this."
Heim, maintaining his cold, monotone, and low-pitched voice, unhesitatingly inserted the cold tip of his scissors into the seam at the side of Shirom's tightly stretched briefs.
The eerie sound of the stiff fabric being cut—snip, snip—reached Shirom's ears relentlessly.
"Stop... Please, I'm telling you, you really can't go any further than that...!"
Ignoring Shirom's pleas, Heim's scissors cleanly cut through the fabric around his waist on both sides, finally splitting the fabric between his legs in two.
The piece of cloth fell limply to the floor with a rustle.
Finally, the last remaining barrier concealing Shirom completely disappeared, and his most shameless parts were suddenly exposed to the cold air of the room.
"Wow... Even after being given an enema and having the smell of his poop pointed out, Shiromu's thing is still standing up straight and strong."
Heim placed the scissors on the table and lowered his cold, ruthless gaze straight down to Shirom's crotch, which was exposed and defenseless.
There, trembling with shame and fear, yet completely aroused by the intense anal stimulation of his first experience, Shirom's small genitals were pointing upwards and hard as a rock, pulsating pathetically.
"N-no, that's not it! This isn't my will... my body just... did it on its own! Don't look at me, don't stare at me with such rude eyes...!"
Shiromu's face turned bright red as if it were boiling, and with tears in his eyes, he shook his head violently while shouting out a polite excuse.
However, Heim's interest lay even deeper than her small genitals, in the most hidden, innermost part.
"The genitals are nice, but the real fun is definitely the anus. It's amazing... because of that enema earlier, her asshole is still twitching and spasming."
Heim gently spread Shirom's buttocks apart with his fingertips and began to give detailed observations of the exposed, delicate anus, as if he were observing a science experiment animal.
"Ah, no...! Don't touch me... Don't look at my butt like that...!"
Shirom writhed in agony at the tingling sensation running through his anus and tried to lift his hips, but his restrained limbs only allowed him to present his anus more clearly to Heim's eyes.
"Besides, because of the stimulation from that enema earlier, it's obvious that the poop deep inside your ass is coming down right up to the bottom. Shiromu's anus has become a loose, stupid hole. There's no way it can withstand 200 milliliters of glycerin liquid flowing into it in this state."
Heim's merciless remark planted a deadly fear in Shirom's mind.
"That's...that's a lie, I can endure it! So please stop preparing for that horrible medical play...!"
Shirom desperately tried to put on a brave face, but Heim simply looked down on him coldly and said, "Hmm...?" before picking up the huge glass enema syringe again for the next, more serious procedure.
[Phase 14] The compounded prescription and the tip of the rectum
Having mercilessly examined Shirom's most hidden and deepest part, his anus, Heim turned back to the tools spread out on the study desk, as if calmly going about his daily routine.
She took out the washbasin she had prepared and tilted the 500ml commercial-sized bottle of glycerin solution that Shirom had pulled out of the closet.
A colorless, transparent liquid with an eerie, viscous consistency is precisely measured out in 60 milliliters and poured into the washbasin.
Next, without hesitation, he added 140 milliliters of tap water that he had prepared beforehand.
"Just as Shirom said, that makes a total of 200 milliliters. We've got a special glycerin enema solution with a concentration of 30 percent."
Heim used a glass rod to stir the liquid in the basin, making a monotonous, rattling sound, to ensure it was completely uniform.
As Shiromu watched the horrifying enema solution, meant to violate him, being coldly mixed right before his eyes, he couldn't stop his teeth from chattering with fear.
"No, please stop, Heim! Putting that much enema fluid into my body is absolutely insane! It's poison!"
"He's not crazy. Shirom himself insisted that this concentration was the perfect enema formula that caused the least stomach pain and allowed him to enjoy only the intense urge to defecate."
Without changing his expression at all, Heim picked up a large, clunky 200-milliliter glass enema syringe.
Then, he dipped the tip of the syringe into the 30 percent enema solution in the basin, and with a heavy sizzling sound, he pulled the syringe back, drawing up all 200 milliliters of enema solution into the glass tube in one go.
A glass enema device with a substantial weight, filled with clear enema fluid.
Heim generously applied lubricating lotion to the tip of the cold glass nozzle with his fingertips, giving it a slimy, obscene sheen.
"Now, Shirom. Let's get started with our real doctor-patient game. I'm going to pour all of this glycerin solution into your asshole and give you an unforgettable enema."
Heim held the glass enema syringe firmly in both hands and slowly knelt down, approaching between Shirom's buttocks, which were completely exposed and vulnerable in a forced M-shaped leg-spread position.
Then, he coldly pressed the nozzle of the lotion-soaked glass enema syringe precisely against the center of Shirom's anus, which was twitching and convulsing in fear.
"Huh...!?"
The moment the cold nozzle touched the mucous membrane of his anus, Shiromu felt a strong shiver run down his spine and let out a scream.
The enema has not yet been inserted.
With the enema ready to be inserted into Shirom's anus at any moment, the liquid injected, and Shirom's intestines filled with an overwhelming urge to defecate, forcibly completing the enema, Heim stopped moving and looked down at Shirom's teary-eyed face.
"...Heim, please, I'm begging you, anything but that...! I only know about it from reading books, I've never actually had an enema before! If you put the tip of such a thick glass enema syringe inside me, I...! I..."
I'm a boy, and yet I'm getting an enema...
Shiromu candidly revealed his inexperience and fear, desperately begging for forgiveness while maintaining a polite tone.
I am now about to experience firsthand the horror that I've always felt when girls in books and games were given enemas and cried out in terror.
"You have the knowledge, but this is your first real enema. Hmm...? So, how do you feel right now? How does it feel just before this thick glass tube is thrust deep into your anus and you're given an extreme enema with 200 milliliters of liquid?"
Heim continued to verbally abuse Shirom in a low, sadistic voice, seemingly tormenting him and fueling his anxiety and fear.
"This is the worst...! I'm so embarrassed, so scared, I feel like I'm going to die...!"
"Nobody dies from embarrassment... It just makes you want to poop until you can't anymore. Hey, Shirom. If you don't want this nozzle shoved any further in and want to be spared the enema right now..."
Heim peered into Shirom's face and uttered a proposal that was both extremely cruel and sweetly seductive.
"Try asking me in a cute voice, 'Big sister, please give me an enema.' If you can say it properly, I might consider whether or not I'll actually give you one."
"What...!?"
Shirom was speechless at the sheer emotional humiliation of the request.
They want me to call my older sister, who always looks down on me, "big sister," and, unbelievably, beg her to "please give me an enema."
There was no way I could ever utter such a humiliating line, not even if my mouth were to split open.
"You can't say it? Well then, I'll proceed with the enema without mercy."
Heim coldly announced, then slowly applied his weight to the nozzle of the glass enema device that was positioned against the anus, pushing it straight in.
Squish!
"Ahhh!?"
The wet, visceral sounds of flesh being forcibly stretched echoed vividly through the quiet room.
With the lubrication of the lotion, the nozzle at the tip of the thick glass enema syringe slid smoothly and surely into the depths of Shiromu's unsuspecting anus, without any resistance whatsoever, yet accompanied by an intense sensation of a foreign object.


[Phase 15] Pleas for surrender and a cold, ruthless line of severance
With a squelching sound of wet flesh rubbing together, the thick, lotion-soaked nozzle of the glass enema device plunged even deeper into Shiromu's defenseless anus.
It wasn't a sharp, blade-like pain, but rather an unknown, weighty sensation he'd never experienced before, mercilessly stretching the mucous membrane of Shirom's immature anus and intensely pressing against the wall of his rectum from the inside.
There's no need to advance the nozzle any further.
Heim's slender fingertips were firmly gripping the syringe at the end of the glass enema device, and if she applied even the slightest pressure, 200 milliliters of cold glycerin enema solution would flood into Shirom's body in an instant.
Based on what he had read in books, Shirom fully understood what would happen if glycerin enema solution were injected into the rectum.
Once that colorless, transparent chemical enters the body, the rectal mucosa is intensely stimulated, triggering an overwhelming urge to defecate, completely against one's will.
200 milliliters is by no means a physical amount that would make your stomach feel completely full.
However, the intense glycerin reaction caused by that exquisite 30 percent concentration is more than enough to frantically awaken the feces accumulated in Shirom's body, instantly plunging him into the hell of guaranteed poop leakage.
Getting an enema means completely losing by soiling yourself in front of Heim.
The worst-case scenario flashed through Shirom's mind, and he felt like he was going crazy with fear and anxiety.
"What's wrong, Shirom? You're so scared, clenching your asshole tight... I can feel your anus trembling all the way to my hand holding the glass enema syringe."
Heim kept his finger on the syringe and looked down at Shirom with cold eyes, without losing the slightest hint of his low-key demeanor.
"Hey, I'll ask you one more time. If you don't want to get this powerful enema right now and end up shitting your pants on my lap...you know what you should say, right?"
Heim, in a voice as emotionless as someone training a poorly performing mouse, demanded the same humiliating words again.
"Say in a cute voice, 'Big sister, please give me an enema.' If you can say it properly, I might just let you off the hook for the enema right now."
The moment he heard those words, the last vestiges of male pride left in Shirom ignited a fierce flame of defiance.
"I-I would never say that...! I absolutely refuse to say something so embarrassing! I will never give in...!"
With teary eyes, Shirom glared fiercely at Heim, biting his trembling lip, and shouted in a polite tone, his voice filled with desperate rejection.
Calling his twin sister, who had always looked down on him and whom he had long harbored the desire to punish, "Big Sister," and even going so far as to ask her to "give me an enema," signifies the end of his life as a man and as a younger brother.
I will never tell anyone, I will definitely hold on—telling himself this, Shirom desperately tried to clench his anus.
However, Heim simply dismissed Shirom's stubborn attitude with a scoff.
"Hmm...? Well, no words are needed then. I'll give you an enema right now."
Heim's slender fingertips began to push the syringe of the glass enema device firmly and without any hesitation.
The piston moves, and you can really feel the tip of the clear glycerin enema solution slowly and smoothly entering deep into Silom's anus from inside the glass tube.
"H-ah...!?!?!?!"
Just a few drops of the liquid touching the mucous membrane sent a chilling, unsettling heat through Shirom's rectum, and a heavy, throbbing sensation settled deep inside his stomach, which he hadn't expected.
This is an enema.
The first enema I've ever had.
It really will happen.
If I let them push through like this, everything will be over in an instant, and I'll be turned into a slave covered in shit.
The terror that pushed him to his absolute limits completely shattered Shirom's reason, and he threw away all his pride and dignity, screaming like a madman.
"O-Okay! I'll tell them! I'll tell them, so please stop, Heim...!!"
"So, tell me quickly? My fingers won't stop now."
Heim continued to push the syringe slightly forward, relentlessly forcing the countdown.
"Oh, big sister...! P-please give me an enema...!!"
With his face contorted in a messy, crumpled face, tears and drool streaming down his face, Shirom squeezed out the most shameful and shameless plea of ​​his life in his cute voice, and finally, finally, completely surrendered.
The room echoed emptily with the utterly depraved words of a younger brother begging his older sister for an enema.
Still in a forced M-shaped leg-spread position, Shirom breathed heavily, looking up at Heim with pleading eyes, hoping that this might somehow allow him to avoid the worst-case scenario of being injected.
However, what spilled from Heim's lips was a chillingly thin smile that brutally shattered Shirom's faint hopes.
"...Yes. You said it well. Shiromu begged me from the bottom of her heart in such a cute voice, asking me to 'please give me an enema.' ...Big sister, there's no reason for you to refuse, right?"
"Eh...? Ah, ah, ahhhhh...?!"
The moment Shirom's eyes widened in despair, Heim's hands forcefully pushed the syringe of the glass enema device all the way in.
Slurp!!!!
A massive 200 milliliters of highly concentrated glycerin enema solution rushed into Shirom's rectum from his anus with tremendous force.
As the words suggest, Shirom's own "request" officially kicked off the doomed enema play.




This concludes the trial version.
If you'd like, I'd be happy if you also read the full version.