Deep Dungeon: I’ve been thrown into a game-like world with a class system. Armed with a mediocre ability and no allies, I’ll take it easy and progress at my own pace
“Please conduct the lottery gacha.”
The sensation that had paralyzed me returned as I stared at the words displayed on the massive screen where the blackboard once stood. The continuous string of inexplicable events had overwhelmed me, but now I could finally react with a “What the heck is this gacha thing?” attitude.
I am Keita Matsui, an ordinary high school loner who blends into the shadows.
Today was just another day in my usual routine—sitting quietly at my desk, trying not to draw attention. It was the winter of my second year in high school, and with only a few months left before becoming a third-year, thoughts about exams and future plans were starting to bother me… or maybe they weren’t.
The door should have opened to reveal our thin, rural math teacher.
But the first abnormality wasn’t that—it was outside the window. Outside the window, it had become pitch-black. Not just darkness caused by a lack of light, but an absolute void—”nothingness” might be the best way to describe it. Outside the windows stretched an eerie scene reminiscent of a completely black screen.
Yet inside the classroom, everything remained the same—the colors, the direction of the light—it was as if time had stopped, cutting out the space of the classroom along with us.
Even the blackboard had transformed into a display screen, with stark white letters floating on a black background:
“Welcome to the world of Deep Dungeon.”
Naturally, the energetic students shouted questions out loud, but no one answered them.
In the midst of all this, I remained frozen in shock.
Some students pulled out their smartphones to call or send messages on social media; others began discussing things with friends; some, like me, were simply stunned.
And then came the instruction: “Conduct the lottery gacha.”
How exactly were we supposed to do that?
“Hey, what about your smartphone?”
“Mine’s gone too.”
Ah, so it was about our smartphones.
Wow… Deep Dungeon, whatever that was, had been installed on my phone, and every other app had disappeared—including the ability to make calls or send emails.
All my painstaking efforts up until now… no, it was too early to give up. My account data should still be there, so I might be able to restore it later.
What kind of game is this? Well, it’s clearly some sort of mobile app game.
Honestly, worrying about app games even in a situation like this made me hate myself.
Now, about this so-called Deep Dungeon—it had an overly simplistic interface that failed to spark any interest whatsoever.
Normally, mobile games entice players with flashy visuals: cute anime girls or cool warriors on the title screen. But Deep Dungeon? Just a black screen with plain text—a depressingly lazy start screen. The top half displayed rotating text, while the bottom featured a single button for the gacha. Everything was in monochrome, painfully simple.
Though I wasn’t particularly eager, I decided to check it out since nothing else was visible except the instruction to “Draw the gacha.”
“Let’s begin Deep Dungeon!”
“Draw the gacha to get something that will powerfully support you!”
“You might get ‘Descent,’ ‘Sacred Relic,’ or ‘Truth’!”
…Okay, I got that this was some kind of game mechanic, but there was zero explanation about what kind of game this actually was. What exactly were we supposed to do after drawing the gacha?
Judging from the title Deep Dungeon, maybe it involved exploring a labyrinth?
There was no explanation about how to return to the real world from this strange space either.
Should I just go ahead and draw the gacha without thinking too much? There didn’t seem to be any other options…
Maybe I should ask someone… No, wait. As embarrassing as it is to admit, I’m a purebred loner. Since the start of the second year, I’ve barely spoken to anyone outside of greetings, basic communication, and classwork.
In situations like this, I have a secret weapon: “Eavesdropping.”
“Please conduct the lottery gacha. 21 people remaining.”
Oh, the display on the former blackboard had updated.
“Hey, the message changed!”
“Read it carefully before doing anything.”
“Meh, it probably won’t change much. Hide, just draw it already.”
“Haruto hasn’t changed at all. He’s making all that worrying seem pointless.”
Wow, the two natural leaders of the class had already taken action. First to draw the gacha was the athletic, handsome guy from the kendo club who everyone admired.
The other was the student council president, equally talented in academics and sports, beloved by both boys and girls. Both of them were friendly to everyone, so I’d exchanged a word or two with them before—things like “Good morning”… Hmm, now I’m feeling a bit sad.
If our class were turned into a story, one of those two would definitely be the protagonist. Me? If this were a manga, I’d probably be a tiny background character whose back is barely visible in the corner of a panel.
Speaking of background characters, the two chatting diagonally behind me might qualify. Thinking of people as background characters is rude, I know, but since I’m less than a background character myself, I’ll apologize in advance.
As I mentally apologized, I turned my attention—or rather, overheard the chatter of two more otaku-leaning classmates.
“Hmph, it’s just a game, right?”
“Kinda like a social game, huh?”
“It all depends on whether you get an SSS-rank character from the gacha, doesn’t it?”
“I’d hate it if this were a one-shot deal.”
Hmm, interesting. They were comparing it to social games. Anyone who’s played those would probably think the same thing.
But unlike social games, it didn’t seem possible to reset and reroll in Deep Dungeon. That raised the question of whether spending money on gacha pulls would even work here.
“Whoa, I got ‘Sacred Relic: Kogitsune Maru.’ This really feels like a game.”
“I got ‘Descent: Hero Uppsala.’ No idea who that is.”
“Yeah, can’t search for anything here…”
“True.”
Apparently, the two main characters had drawn Sacred Relic and Descent.
The two otaku-types also mentioned getting Descent and Sacred Relic.
“Please conduct the lottery gacha. 2 people remaining.”
When did the counter on the former blackboard drop to just two people left?
While I was busy using my eavesdropping technique, the situation had progressed far beyond me.
It was about time for me to act… Just as I reached for my phone, I heard a voice.
“Matsui-kun.”
Startled by the girl’s voice, I slipped off my chair.
GAGAGAGA!
An iron rod shot up from the floor, piercing through the chair I had been sitting on.
“A-ah… Th-thanks… You saved me…”
“Uh, um, I noticed you hadn’t touched your phone yet, so I figured you hadn’t drawn the gacha…”
I-I would’ve been seriously injured if she hadn’t called out to me. Thank you… Uh, Yamada-san, right?
She had shoulder-length black hair tied back with a cat-shaped pin, exposing her forehead. With her droopy eyes and raccoon-like face, she was undeniably beautiful—at least, I think so.
Apparently, she ranked among the top three most popular girls in the class. Honestly, I don’t pay much attention to these things.
Being unaccustomed to being spoken to worked in my favor. Slipping off my chair from sheer surprise was embarrassing, but it ended up saving me, so I couldn’t complain.
Still sitting on the floor, I looked up at the blackboard display. Only one person remained. The pressure to hurry and draw the gacha was clear.
“Do as instructed, or else,” it seemed to say. Scary stuff.
Fine, fine. I’ll draw it, okay?
“‘Truth: Knowledgeable Dolphin’ obtained.”
Ugh… I knew it. I knew it all along. A result like this was fitting for someone as insignificant as me.
But maybe it was too soon to judge. After all, I still didn’t know what this “Knowledgeable Dolphin” could do.
