Chapter 1

Little God’s Paradise Dungeon
A somewhat curious college student, Asuma Takuya, got caught in a ground fissure and ended up becoming a Dungeon Master in another world.
On top of that, his body regressed into that of a child. He couldn’t go back home, even if he wanted to!

So, using his modern knowledge and the power of the dungeon, he began a new life.
But as the dungeon gradually became more comfortable to live in, people started gathering around the childlike Asuma, revering him as the “Little God.”
And soon enough, the dungeon stopped being a dungeon at all.

This is the story of him creating dungeon-bred GMO crops, puzzling over the gap between his body’s age and his real age, protecting the village, being doted on by believers, and building a paradise—while slowly searching for a way home.
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Having Enough to Eat and Knowing the Dungeon*1
The dungeon is a system that devours all matter and converts it into mana.

The dungeon is a system that uses mana to create anything.

The dungeon acts in search of new mana.

The dungeon may sleep, but it does not perish.

The dungeon waits for its master.

… Into such a dungeon, a single human fell.

The one who would become the dungeon’s master, a lost wanderer from another world—
a young man named Asuma Takuya.

… No.

Just a moment ago, he was a young man—
now, he’s a boy.

“AAAAAH!? I shrank!? I shrank, right!? Why!?”

Because the dungeon had accidentally “eaten” him, this human had been turned into a child—
and was in utter confusion… and then.

“… Er, first things first, let’s grasp the situation. Did my stuff make it here…?”

Surprisingly, he pulled himself together quickly.

… That stubborn resilience, along with his innate kindness, would later cause people to call him the Dungeon’s Little God.

Of course, he didn’t know that yet.
At the time, all he could despair about was, “My underwear’s gone!”

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Chapter One: I’ll Make This Dungeon a Paradise!
Now then.

My name’s Asuma Takuya. Just a plain ol’ first-year college student.

Earlier today, right after I bought lunch at the campus co-op and walked out, the ground split open beneath me. I fell in—and now, for some reason, I’m a child standing here!

… I don’t understand a thing about this situation.
And yeah, I’m seriously troubled right now.
What is this! Somebody explain!

But just being troubled only makes things worse. To avoid being troubled, I can’t let myself be troubled. So I mustn’t panic—ahhhhhh.

… Okay, let’s sort things out. First, my surroundings.

Looking around, it’s rocky walls as far as I can see. Looking up, also rocky walls. Seems like I’m in some underground cavern.

But the fact I can see all this means there’s some kind of light source.
Right—this cavern has a really high ceiling, and at the very top, I can see something like a crack, shining with mysterious sparkles.

That’s probably where I fell through…
Which means, on the other side, the path in front of the co-op at my university is still connected. I have a faint hope, anyway.

But it’s way too high to reach, so I’ll shelve that for now. Next.

My belongings.

Here, the situation’s devastating.
See, my body shrank down to about the size of an early elementary schooler!

So naturally, my belt no longer held, my pants slipped off, and my underwear must’ve gone with them. Yeah.

… Right now, the only thing I’m wearing is an oversized T-shirt.

The lower half of me is breezy. This overly liberating feeling has my “son” crying out, “I can’t calm down!”
Oh, God! What did I do to deserve this? Was chasing pigeons around campus such a terrible sin? Oh, God!

Anyway, putting aside God and underwear…
My smartphone that was in my pants pocket is gone, and so is my smartwatch that should’ve been on my left wrist. Those were expensive!

As for my bag, I did find it lying near where I’d collapsed… but for some reason, only my laptop was completely gone.

My notebooks, pens, and the BLT sandwich I just bought—along with the receipt—all of that’s still intact, untouched.
It doesn’t look like it was looted, so I can only tilt my head in confusion. What’s up with that?

Now, about my body.

… What I know is, I’ve got the body of an early-grade schoolkid.

No mirror handy, so I can’t check the whole picture, but from what I can see, yeah, that’s the deal. My arms are thin and short, and I’m weak.
The bag full of textbooks and notebooks I could easily carry before now feels heavy as hell.

At least, since my body’s smaller, the baggy T-shirt covers my bottom half, saving me from full exposure. Thanks, T-shirt.

And then there’s another change…

“… What’s this, I wonder…”

On my left wrist is a bracelet I don’t recognize.

No seam.

… Which means, I can’t take it off.

That’s scary!

I tugged and poked at it, but it wouldn’t budge, gripping my wrist tight.

It’s right where my smartwatch used to be, so I thought, “Huh? Did my smartwatch transform?”
… But nah, probably not. So what is this?

“… Huh?”

As I rubbed and stared at the bracelet, I noticed there were letters inscribed on it.

And then, I realized.

They didn’t look like any language I knew, but I still recognized them as “letters”…
And more than that—I could read them.

> The dungeon is a system that devours all matter and converts it into mana.
> The dungeon is a system that uses mana to create anything.
> The dungeon acts in search of new mana.
> The dungeon may sleep, but it does not perish.
> The dungeon waits for its master.

The moment I read those words, the last line—“The dungeon waits for its master”—shone brightly, then vanished.

Startled, something suddenly clicked in my mind.

“… The dungeon is a system that devours all matter and converts it into mana…”

Muttering, I picked up a stone nearby and focused.

… The stone vanished, and in its place, information poured into my head.

“Granite.”
Breaking it down further: “Feldspar, Quartz, Mica, Hornblende, Magnetite, Zircon, Garnet.”
And broken down even more: “Silicon, Oxygen, Calcium, Aluminum, Sodium, Sulfur”…

Information flowed, and flowed, and flowed…

… Until at last, all that information became simply “Mana.”

“… So this is the dungeon’s function, huh.”

Judging by the writing on the bracelet, I’d just used the dungeon’s ability to break down the stone, convert it into mana, and absorb it.

And considering the inscription that disappeared…

“So, I’m the dungeon’s master, huh.”

… Apparently, I’d become the dungeon master. I don’t really get it, but…

Well, if I don’t get it, I’ll just have to test it out.
Alright, I like this kind of thing. Time for experiments!

“Now then, the granite’s gone… so what now?”

First off, the granite I was holding.

It just vanished. Poof. But that’s probably what “The dungeon is a system that devours all matter and converts it into mana” was talking about.

Which means…

“Maybe I can bring it back out? Since it’s also supposed to ‘use mana to create anything.’”

Might as well try summoning granite again.

… And just like that, a granite block popped into my hand. Oh!

“… So, I can change the form, huh.”

The plain stone had become a block. That means I can reshape it.

Wait, hang on—better confirm. I dismissed the block, then tried summoning it back in its original pebble form.

A pebble appeared.

“… Can I split it up, maybe? Like into quartz and feldspar…?”

I broke the pebble down again, then focused on reconstructing it into separate components.

… Sure enough, I got a transparent crystal, an opaque one, and a dark lump that screamed “miscellaneous!”

“So it works! I see, I see… hooooh.”

Now this was getting fun. If I could do this, things were gonna get real interesting.

For instance—remember, granite contains magnetite. And the walls of this cavern look like granite too…

“… That means I can make iron.”

So, I’d secured an iron supply. Way to go, dungeon.

“Wait, then… can I turn granite into something totally different? Like, say, gold…?”

But when I tried making gold out of granite, it didn’t work.

Hmm. Maybe mana can only reconstruct things I’ve already absorbed, or only recreate the original materials?

Alright then—let’s try something else. I rummaged in my bag and pulled out a tissue. Absorbed it.

“Can I mass-produce tissues? … I can, but, ahhh—I see, so it’s inefficient.”

I made about three tissues. It worked, but the cost was ridiculous. Three tissues drained as much mana as one kid-sized granite pebble. Definitely not mass-based.
Looks like granite-mana is best for granite, and tissue-mana is best for tissues.

“I see… so when I break something down, I get its info, and it keeps breaking down further until it all becomes mana…?”

After a few rounds of absorption and reconstruction, I understood one thing: it’s best to just absorb things into mana first.

That way, I can store matter as mana, and then use it to recreate things later.

Although, there does seem to be a concept of “materials.” Like how making tissues out of granite was horribly inefficient.

Probably, aside from mana, the dungeon also keeps a stock of elements. Then when I create something, it consumes those. If an element’s missing, mana gets converted to make up for it—which kills efficiency. That’d explain things.

So, I can’t make gold from stone because I’ve never absorbed gold before. Man, I’d love to try alchemy…

“Alright, alright, I’m getting the hang of this.”

So, I’ve figured out the basics of this ability. Next, I’ll use it to survive, get my original age back, and find a way home.

Looking up, I can see that glittering rift far above. Just reaching that will be tough enough, but regaining my old body? Even harder. Not a clue where to start.

Well, I’ll just have to search steadily for a way. First priority is survival…

… Which brings me to the most urgent thing I need to create. And that is…

“First off… I really want some underwear!”

Underwear.
Because my son is still lost in the unprecedented freedom of this situation…

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