As I slowly woke up, I was greeted by an unfamiliar ceiling.I looked around blankly. It was a small room, yet full of life. The furniture, the color of the walls, and the randomly posted posters all left a strong impression.
Where is this?Why am I sleeping in a place like this?
With a question mark dancing in my mind, I slowly stood up.
"Ah, Brother, you finally woke up? Really, how long are you going to stay in bed? Don't tell me you've forgotten what day it is!"
Suddenly, I noticed a girl with twin ponytails standing beside the bed.
And that's where the problem began — I swear, I don't have a sister.
I woke up in an unfamiliar room, and a girl claiming to be my sister was trying to wake me up.To put it bluntly, this situation was… bad. It could only make anyone think they'd gone crazy.
However, a sense of déjà vu flashed through my mind. This arrogant girl who called herself my sister — I felt like I'd seen her somewhere before.
I desperately tried to recall my memories from last night.Right… yesterday, I had been testing how many times I could "fire shots" in one day — thirteen, if I remember correctly.
That's right. I was reading my favorite erotic manga — "In This World of all girl, I'm the Only Boy at School."With that thought in mind, I had wanted to reach a new peak never seen before.It seems that instead of ascending to new heights, I fell flat on my face.
And that's when I realized it.
Yes, of course — the girl standing in front of me, looking puzzled, was familiar.She was one of the heroines from "In This World of all girl, I'm the Only Boy at School."The protagonist's sister.
"Um, miss… what's your name?"
"Huh? Why the honorifics? Don't joke around. I'm Miken. Obviously."
A beautiful girl from an erotic manga who claims to be my sister.
My name is Miken Ayato. If she really is my sister, then it makes sense for her surname to be Miken too.But in the manga, her name was Nikaido Momoka.
What the hell is going on?Is this a prank? A dream?
But would anyone really go to the trouble of making a prank based on an erotic manga?And it's far too realistic to be a dream.
"Hey, is everything okay? You'd better hurry and eat breakfast, or you'll be late."
"...Ah, yeah. I'll go wash my face first."
I answered weakly and walked out of the room like a zombie.It seemed I was on the second floor. I went down the stairs and roughly opened the door to what looked like a bathroom.
The face reflected in the mirror wasn't the protagonist of any erotic manga.It was just an extremely ordinary, mediocre man — me.
It would've been nice if I could've become the main character of an erotic manga just like that.Actually, I really wish that were the case.
Anyway, I needed to figure out what was going on.I walked toward the source of movement.
In the kitchen, Miken had just finished preparing breakfast. On the table sat what appeared to be my meal — toast covered with blueberry jam, and coffee topped with exactly two sugar cubes.
Every single thing was just the way I liked it.The moment I saw it, a strange warmth filled my chest.
…I see. If she's my sister, of course she'd know what I like to eat.Otherwise, there's no way she could've guessed.
There were countless questions I needed to ask — but I swallowed them down along with a sip of coffee.
A thought suddenly came to me — the "World Five Minutes Ago Hypothesis."As Bertrand Russell proposed: "The world might have been created five minutes ago, and all our memories of the past could have been formed at the same time."
There's no evidence to disprove it.Therefore, I couldn't rule out the possibility that this world was a reconstructed version of that erotic manga — with me as the protagonist.
As absurd as it sounded… I kind of wanted to believe it.
I cast my gaze toward Miken sitting opposite me. She was playing with her phone, drinking milk, and chewing her bread without a care in the world.Her actions were natural — completely unguarded.If this was acting, then even being deceived would be worth it.
"Sis, I have to ask you a few questions. Please answer within five seconds."
"Huh? Why so suddenly? Brother, did you hit your head or something?"
"Don't joke around. This is a serious Q&A between siblings. Prove to me that you really love me."
"Ah—no love at all… fine, whatever. Ask away."
She looked up from her phone, slightly annoyed.
"What's my birthday?""February 9th."
"What's my favorite food?""Salt butter ramen."
"What was the name of the dog we used to have?""Peko Maru."
"What's my favorite color?""Black and ultramarine."
"What type of woman do I like?""…Tch, big breasts."
Did she just click her tongue at that last part?So, Nikaido Momoka really does have a complex about her small chest.
"What's my motto?""…Huh? I don't know."
Well, that's expected. I don't have one anyway.
"Alright, last question. What color underwear are you wearing right now?"
"Wha—!? P-Pink… wait, why would you ask that!? Isn't it usually the other way around?"
"Ah, you're right. Normally it's the woman asking that, isn't it?"
"Of course! Ugh, I'm not interested, though!"
I see. So that's how it is.
At that moment, I began to accept this reality — whether it was crazy or not didn't matter anymore.
"Oh no! It's so late! I'll hate you if we're late, Brother! Being late on the first day of transfer would be the worst!"
Miken hurriedly stood up. On the sofa lay a neatly folded school uniform.
As I was about to change clothes right there, Miken yelled in embarrassment.
"Hey! Don't change in front of a girl! Even if I'm your sister, that's not okay!"
She glanced at me — maybe a bit too much.It seemed my "sister" was a little too interested in men's bodies.
Anyway, first day of transfer, huh?This really was following the story of the erotic manga to the letter.
So I decided to go to school with Momoka — no, Miken.
Private Sakamo Academy.Originally an all-girls school, but due to declining birth rates, it became co-ed starting this year — that's the setting of the story.
I was taken to the staff room, greeted my homeroom teacher briefly, and was led to my new classroom.
The sign on the door read 2-B.As I reached for the handle, I couldn't help but feel a strange sense of rebirth.Maybe this door was the gateway to my new life.
Dozens of curious eyes turned toward me the moment I stepped in.A crowd of girls — excitement, curiosity, and something more flickered in their gazes.Their eyes roamed over me — my neck, collarbone, abs… and beyond.
A garden of beasts.And I was the lone, helpless sheep thrown into the carnivore's cage.
I took a deep breath and declared, as if announcing to the entire world:
"Nice to meet you all. My name is Rei Ayato. I'm the only boy in this school, so please treat me kindly."
At this point, it would be foolish to doubt it any longer.It seemed this really was the world of that erotic manga.