Dan☆Boru: The School Dungeon Master Devours His Sleep

My name is Masuda Keima. I'm a high school student attending Meikyuu High School's Dungeon Department. My age is around 16.

Getting right to it, I was running. I'd completely overslept. When the clock's hands pointed to 8 o'clock, I couldn't help but let out an "Oh…" like something out of an American comic at my now-certain tardiness.

"Even though second year is when the real Dungeon Studies classes finally start… I really screwed up."

That's right, today was our first Dungeon Studies class. For me, someone with the ambition of becoming a Dungeon Master who makes monsters do all the work while I spend my days leisurely sleeping, this was an absolutely unmissable class.

I jumped over the deserted front gate, changed into my indoor shoes at the shoe lockers, and headed to the second-year classroom.

Class had already started. Crap, come to think of it, weren't we supposed to decide something important today—

"Sorry, I overslept!"

—When I threw open the classroom door with great vigor, somehow, everyone was already paired up in groups of two.

And at the lectern, Haku-sensei—known as the White Goddess, and looking great in black stockings—was staring at me with a surprised expression. Umm. Did I do something wrong? Oh, was I too loud considering I was late? Sorry.

"Sensei! Um, would it be alright if I pair up with him?!"

"Eh, ah, well…"

"Nice to meet you! Umm, what was your name again?"

And then a girl—a beautiful blonde with blue eyes who had apparently been talking to Haku-sensei—called out to me.

"… Ah, um, Masuda Keima. Nice to meet you."

"Kehma, then. I'm Number 695."

"Oh! A number name! You're from Yaminokami?"

Oh, Yaminokami is the name of a multi-species region. It's home to various species—fantastical ones like dragons and unicorns, monster-like ones like lizardmen and living armors, and even giant snakes and slug-like creatures.

One characteristic is that their names are often "numbers."

Well, she looks like a normal human, but maybe she's already acquired a humanization skill?

"But since a number is hard to call you by, can I call you Rokuko-san?"

"Well, it would be hard for a human to say, so that's fine. You don't need the 'san' either. Nice to meet you."

Rokuko and I shook hands again.

"So, what kind of pair is this? Like a one-on-one battle pair or something?"

"Eh, no, it's a Core-Master pair. For one year."

"… Isn't that a super important pair?"

"It's a super important pair."

A dungeon requires two people: a "Core" and a "Master." Strictly speaking, you can do without a Master, but having one is preferable. The "Core" deploys the dungeon while the "Master" operates it. With enough effort you could deploy and operate simultaneously, but the flip side is that it puts that much more strain on you. Better to just work as a pair.

And being paired up means… we're basically partners.

I'm the one who overslept on such an important decision day, but…

"Umm, are you aiming to be a Core by any chance?"

"No, I'm aiming to be a Master though."

"Great. I'm aiming to be a Core."

"Lucky me, getting to pair up with someone from Yaminokami."

Those from Yaminokami universally have ridiculously high aptitude values for both Core and Master. In other words, they're the elite of the Dungeon Department.

Regarding aptitude values, while the human race is said to average 25:25 for Core:Master, Yaminokami natives average 50:50. That's twice as much.

Me? I'm 15:35, leaning toward Master. My Master aptitude is quite a bit above the human average.

When these aptitude values are high—well, to put it simply, it changes things like the upper limit of power you can draw from a dungeon.

Huh? But if she's such an elite from Yaminokami, shouldn't she normally be in high demand? Why was she left until the very end?

～ Next Episode Preview ～

For some reason, Rokuko had been left alone. The reason became clear during the dungeon practicum!

"Say, Rokuko-san, what's your aptitude value?"

"…19:10."

"Hm? 10:90? You're suited to be a Master then."

"…19:10! Core 19, Master 10… uuu."

"Huh?"

"Are you going to make me say it again!?"

"… You're from Yaminokami, right?"

"Excuse me for being a dropout!"

"Well, my plan for the future is to run a leisurely dungeon in some rural backwater, catering to elderly folks while I sunbathe all day. I couldn't care less if you're a dropout."

"… That's annoying in its own way!?"

And Rokuko turned out to be Haku-sensei's little sister!

"Because of you, my ambition to become Rokuko-chan's partner is ruined, you know?"

"But wait, wasn't the class set up to have an even number of students from the start?"

"Be quiet! I'll determine whether you're worthy of being my little sister's partner. A Dungeon Battle. If you lose, you'll quietly hand over that partner spot."

"… Sensei! Then I'd have to take classes alone!?"

What fate awaits Kehma and the others—!?

(To be continued… not!)