It was a letter.

“What’s this?”

I picked up the envelope.

It seemed like someone had slipped it through the mailbox slot… Why a letter out of the blue?

I examined the envelope in the light. Fortunately, there didn’t seem to be any strange objects inside, like a cutter knife, for example.

“Who could have sent this?”

I looked around quickly. Everyone seemed to avoid making eye contact with me…

“…This feels uneasy.”

Having already experienced the gym storage room incident, I had a premonition that this letter might not bring good news.

“For something that suddenly appeared in this world, it hasn’t really helped me.”

Feeling uneasy, I shook the envelope lightly at my fingertips.

“Uh, ominous. It’s ominous.”

Returning to my seat, I placed the letter on the desk and stared at it with clenched fists.

“Hmm…”

What should I do with this?

I found myself in serious contemplation.

Since it came to me, I should probably read it, but… No. Should I just pretend I didn’t see it and move on?

“There doesn’t seem to be anything particularly noticeable at first glance.”

The envelope was just an ordinary type sold at the store. Judging by the design, it might have been sent by a girl, but it wasn’t certain.

“There’s no sender’s name.”

I examined the envelope from different angles, but it was clean. There were no clues to identify the person who wrote it.

“The contents seem to be just ordinary paper.”

At least it didn’t seem like an attempt to harm me.

“No, but after putting it this way, the content could still be violent…”

I shouldn’t let my guard down yet. Even though it’s me, suddenly receiving abusive language wouldn’t be pleasant.

I returned to contemplation mode.

Indeed.

It’s truly one thing after another.

“Why would someone from Inso send a letter like this?”

This time, I couldn’t think of anything specific.

“I’ve only received birthday cards in my life.”

Even those have been replaced by mobile messages as I grew up. It’s been a really long time since I’ve seen such an analog letter.

“Considering my ruined relationships, it definitely won’t contain anything heartwarming.”

Moreover, in this age without texts, why bother with a letter?

“Well, I don’t know.”

Could it be that I’m about to die?

Even in this chaotic Inso world, text alone shouldn’t be able to kill me.

“Let’s just read it quickly and get it over with.”

I tore open the envelope in irritation.

Rip.

“What could be written in this?”

I unfolded the neatly folded letter.

And the moment I checked the contents inside, I blinked.

After school, on the rooftop.

“…Huh?”

The letter’s content was a duel arena.

“No matter how you look at it, this seems like something I shouldn’t get involved in.”

I thought while steadfastly moving my steps towards the stairs.

“Let’s see it on the rooftop? Isn’t this basically an invitation to a fight?”
Countless dramas, movies, and comics have portrayed rooftops as the battleground for duels. The famous line, ‘Follow me to the rooftop,’ is no exception… The probability of positive events occurring on the rooftop is close to zero.

Of course, special events do happen on rooftops. For example, sharing lunch or playing games like tag.

“But no one would go to the extent of sending a letter for that.”

Moreover, would anyone at my current stage of life even suggest doing such things together?

Considering everything, the hypothesis of a duel arena seemed the most plausible.

“But is the school rooftop usually open? Isn’t it usually locked?”

There might have been some fire safety regulations… but from my memories of attending school, it was never open.

“But this is Inso World. It’s definitely open.”

Originally, the school rooftop was the sacred place of delinquents in the early 2000s. It couldn’t be anything but a convenient and careless worldview.

“What crazy thing is going to happen today…?”

With a mix of excitement and discomfort, I headed towards the rooftop.

Finally, I arrived at the rooftop door.

With a pounding heart, I placed my hand on the doorknob.

Then…

Creak.

“It’s really opening…?”

I expected it, but it was still surprising. I had secretly hoped the door would be locked, so I wouldn’t have to go to the rooftop.

I peeked inside the rooftop with a slight tilt of my head.

“Hmm.”

Fortunately, no one was there yet.

“For now, let’s go back.”

I closed the door again and descended the stairs.

“Now I need to decide whether to go for real.”

I weighed the situation in my mind.

Advantages of going to the rooftop: I can find out who sent the letter. Curiosity satisfied. Disadvantages: I don’t know what might happen.

Advantages of not going to the rooftop: Nothing happens. Disadvantages: Ignoring it might lead to bigger trouble later.

Well, it’s better not to go, obviously.

It wasn’t something worth mentioning at this point, but it was the expected result.

“Yeah, even if I try, it’ll probably be another fan club or something. Let’s not be curious and just go back.”