The World Became One Where Sex Is a Compulsory Subject

I was twenty years old. The first thing I did after graduating high school was lock myself in my room and start writing. College? I had no plans to go. I figured I could make a living just fine from my novels. The proof of that was the story I’d stockpiled back when I was still a high schooler. A nineteen-plus web novel I’d uploaded the moment I turned twenty, right after finishing two hundred chapters. Honestly, I never expected that many people to read it, but it turned out to be a pretty successful work. And now, riding that momentum, I was working on my next one.

Tap. Tap. Tap.

The sound of my keyboard echoed quietly through the dark room.

Tap!

“Ugh—this isn’t it.”

But only a few minutes later, I had to stop typing. I’d already hammered out the protagonist’s setting and the world-building, but… how should I put it? It just didn’t feel right.

“I went full throttle on the hardcore stuff to match my tastes, too.”

Just like my previous work—BDSM, latex, human furniture, neglect play, the whole lineup. I’d poured every last one of my fetishes into the setting, yet the words kept getting stuck. So stuck that even my dick refused to get hard.

“Ugh… is this what they call a slump?”

I’d only finished one story and I was already in a slump? This was the third time I’d scrapped everything before I could even start writing. It had been exactly one month since I wrapped up my debut. Maybe the unexpected success of that first book had made me greedy. I kept thinking I had to do even better this time. Was this the infamous author’s disease I’d only ever heard about?

‘Hmm… in times like this…’

I vaguely remembered something I’d read somewhere. A way to overcome a slump. They said you should try writing something new, right?

“Let’s see… what genres haven’t I tried yet…”

Even though I said that, I only had one completed work under my belt. There were far more genres I hadn’t touched than ones I had. Still, picking just one out of all of them was…

‘Guess I’ll spin the internet pinball wheel or something…’

I decided I’d write whatever genre the wheel landed on. I threw in academy, tower climbing, gender-bender—pretty much everything. And when the wheel finally stopped, the result was—

‘Academy?’

School, huh… I didn’t exactly have fond memories of school, so I was a little reluctant, but I figured I could probably pull it off.

“……Ah.”

That was when it happened. Like a fuse had been lit inside my head, a decent idea sparked and crackled to life.

“Oh.”

It actually worked? Slump overcome. Alright, let’s do this.

First, the setting would be a school. Among the compulsory liberal arts subjects, I’d add a ‘Sex’ course. And I’d make it far more important than any of the others.

‘Ah.’

I couldn’t write a novel aimed at minors. So I’d make all the characters in the story college students… No, wait. ‘Let’s turn high school into a five-year system.’

That meant the educational system in the world I created would be 6-3-5 instead of the usual 6-3-3. And students would start learning the Sex subject from their fourth year of high school—exactly when they turned twenty.

“Hmm… feels a little lacking.”

I’d finally made ‘sex’ part of mandatory education. But instead of simply changing people’s perception to ‘Sex is a compulsory liberal arts subject that everyone must learn,’ maybe I should add something more. Something mysterious and impossible to explain.

‘Oh, this is good.’

Let’s add a setting where a mysterious power prevents men from perceiving the concept of ‘sex’ until they become adults. They can’t hear about it, and they can’t recognize it even if they see it happening. Simply put, men remain completely ignorant about sex until they turn twenty.

On the other hand, women are unaffected by this restriction. So from a young age, they receive sex education as if it were mandatory schooling, and they teach men about sex.

Oh! I also wanted scenes with sex play that would be impossible in reality, so maybe I should advance technology a bit. If a student was late or misbehaved, they could be punished by being encased in latex or plaster and subjected to sexual torture. That didn’t sound half bad.

‘This is nice too.’

For the boys’ sex training, the girls could disguise themselves as realistic dolls to help out—and… and also… Let’s give the protagonist one superpower. Something like the ability to read other people’s minds should be fine, right?

“……Ah.”

My thoughts suddenly cut off there.

I stared blankly at my memo pad.

“……This is a fucking mess.”

I’d gotten too excited and thrown in settings without any restraint. If I actually wrote a novel with all this, what kind of story would even come out?

“Sigh… I’ve really lost it.”

A dry laugh escaped me. I’d created this dizzyingly chaotic world. I must have been under a lot more stress than I realized. No wonder—I’d spent an entire month just staring at my computer, fiddling with settings.

“That’s enough for today. Time to sleep.”

I got up from my chair and headed to bed. The only thought in my head was that I needed to get some rest.

“……Mmm.”

The next day, I woke up. For once, I’d actually gotten up in the morning. And not just any morning—six o’clock sharp.

‘I definitely went to bed at three in the morning yesterday…’

That meant I’d only slept three hours, so why did I feel so refreshed? Whatever. I could just go back to sleep. Even if I felt fine now, I might crash later. My usual active hours started at one in the afternoon, so I needed at least nine hours of solid sleep.

Knock. Knock.

That was when it happened.

“Huh?”

I heard knocking, followed immediately by the door swinging open. It was my mom.

I rubbed my eyes, sat up, and looked at her.

“Mmm… Mom, what’s up?”

“Kim Taejun! Aren’t you getting ready for school?”

“……? What school?”

“Are you still half-asleep? The new semester starts today. You have to go to school!”

“Didn’t I already graduate?”

“Did you have some kind of weird dream? Hurry up, wash your face and come down for breakfast.”

“……Huh?”

……What the hell was going on? Was I still dreaming?

Something was seriously off.

“So Taejun, you’re a fourth-year now, right?”

“What fourth-year?”

“Fourth year of high school.”

That came from my dad, sitting across the dining table. Fourth year of high school? This wasn’t some elementary school kid’s joke.

“I wonder if Taejun’s restriction has been lifted too?”

“Excuse me? Restriction?”

“You’ll find out once you get to school.”

Restriction? What the hell was a restriction? No, that wasn’t even the important part right now. There was something far more distracting than what my dad was saying.

‘……What the hell is that?’

The situation was already confusing enough, but what I saw in front of me was even worse. In fact, that was why I couldn’t focus on my dad’s words. Above my father’s head floated a speech bubble shaped like a cloud—the kind you’d see in a webtoon. It looked exactly like someone’s thoughts being displayed as a speech bubble. And inside it, there was even a sentence written.

……Excuse me? Learn what?

Sex?

“When you get to the dorm, make sure you listen to the dorm supervisor. Study hard. Got it?”

“……Yes?”

Dorm? That dorm?

“If you’re done eating, get ready. I’ll drive you.”

I nodded with a dazed expression and went back to my room. I sat on the edge of the bed, lost in thought.

“……Maybe a hidden camera?”

No, our family was pretty conservative. Knowing my dad’s personality, there was no way he’d install hidden cameras. Besides, the whole speech bubble above someone’s head thing didn’t make any sense to begin with.

Anyway, if I organized what my dad had said:

Name: Kim Taejun.

Age: 20.

Fourth year of high school.

That was my current setting.

“Wow.”

This was ridiculous. Really.

‘Did I somehow fall into some weird world?’

But it felt strangely familiar.

“……Fourth year of high school.”

A five-year high school system.

“And…… the restriction?”

Finally, the ability to read other people’s thoughts.

Ah. No way.

“The settings I came up with yesterday?”

It matched every single thing I’d written down last night, perfectly. So did that mean this was the world of the novel I’d only created settings for? Or more accurately, had those settings been applied to reality?

“Holy shit.”

Was this actually happening?

I was riding in my dad’s car on the way to school. During the drive, I saw several pieces of evidence that confirmed this world was exactly what I’d only set up the night before.

The most obvious was the color of people’s hair.

‘It’s so fucking colorful.’

How could someone have pink hair? Or sky-blue? It was so absurd I could only laugh dryly.

“We’re here.”

My dad stopped the car a short distance from the main gate and turned to look at me. It seemed like he had something else to say.

“Study hard. You know which class you’re in, right?”

“Huh? Oh, yeah.”

I nodded for now. The truth was, the high school I was supposedly attending now wasn’t the one I’d actually gone to. It was a completely different school. The uniform alone was different. I had no idea where anything was, and I didn’t even know which class I was in.

“Listen to your teachers and call home often.”

“Ah, got it.”

……Looking at him like this, he really was my dad. Still, I couldn’t believe that strict father of mine had been thinking about sex.

“Have a good day.”

“Yeah.”

After getting out of the car, I followed the other students wearing the same uniform toward the school gate. First, I needed to find my classroom.

But… how?

Luckily, I was able to figure out which class I was in pretty quickly. There was a class assignment chart posted on the bulletin board in the school entrance hall. My class was 4th Year Class A.

The problem was…

‘Why is the building so far away?’

The classroom was in a building right next to the main building. On top of that, the numbered classes and alphabet classes were completely separated. Classes 1 through ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠5 used the main building, while Classes A through E used the annex right beside it. I had no idea why.

Actually, never mind that—why were there so many classes in the first place?

‘It doesn’t even look like there are that many students.’

Each class had a whopping eighteen students. The funny part ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠was that was only for the numbered classes. The alphabet classes had an absurdly small number. Exactly eight students. Class A had eight, Class B had eight, and Class C had zero.

‘Why even make Class C then?’

Wouldn’t it make more sense to reduce the number of classrooms and just combine the students? I couldn’t figure out why they’d set it up like this.

‘Ugh, this feels suspicious.’

It was like some urban legend about Napoli or something. There had to be a reason they separated the numbered classes from the alphabet ones, right?

For now… I had no choice but to leave the main building and head toward the annex where my classroom was.

But… the inside of the building felt off. Why? Because—

‘They’ve blacked out all the staff room windows on the first floor.’

Every window of the first-floor staff room was completely covered in black, as if to prevent anyone from looking inside.

‘Is this genre actually horror?’

Did I really write these settings? I didn’t remember making anything like this.

I swallowed ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠hard and headed up to the second floor. The second floor was at least a little better.

4th Year Class A.

When I entered the classroom, the other students were already there. Of course, their hair colors were just as colorful. I didn’t think I’d ever get used to that.

I walked over to the seat with my name on it.

But then—

‘Ah.’

I was fucked.

The girl sitting next to me had a face that was anything but ordinary. Golden blonde hair, crimson eyes, and a red Adidas jumper. Just by looking at her features, it was obvious she was a total delinquent.