Chapter 1

From M Novels, Volumes 1-2 are now on sale.

From Monster Comics, Volumes 1-4 are now on sale.

On Piccoma, the WebToon adaptation of this work is currently being serialized. (Title: I'm the Only One to Conquer the Hidden Dungeon)

※There are differences between the web, book, manga, and WebToon versions.※

That day, I suddenly fell into a dungeon.

This was the beginning of it all.

******************************

That day, I finished my usual run and bought breakfast at a convenience store.

My plan for the day was to guard my house instead of going to high school.

My job is what people generally call a NEET.

Come to think of it, a friend I met online once asked me why a NEET would even bother working out.

It's simple.

My job is to guard the house, and I can't do that with a flabby belly.

While thinking about this, I skipped home, gazing absentmindedly at the rising sun that was just starting to peek over the endless fields.

Just as the world was beginning to light up, the world in front of me suddenly turned dark.

But that wasn't all.

"AAAAHHHHH!!!"

I'm currently in the middle of a free fall and screaming.

It feels like I'm doing a bungee jump without a safety harness.

I'm trying to describe the situation, but I'm so scared I might wet my pants.

It's pitch black.

If I keep falling at this speed, I'll definitely die.

So, I try various positions like skydiving without a parachute... but...

Well, I knew it wouldn't slow me down at all.

Then,

my vision and thoughts started to slow down.

Ah, this must be the "life flashing before my eyes" thing.

I'm dead, good job me, and goodbye... Poof.

...Wait, what?

On closer inspection, it seems I'm physically slowing down.

The gravity feels lighter.

No, this is definitely slowing down.

Seriously,

isn't this completely ignoring the laws of physics?

What, is this magic or something?

Then, my feet hit the ground without any impact.

"I arrived safely, but it's too dark to see anything."

As I muttered this, my vision gradually brightened.

The room was illuminated by a warm, orange light, different from the morning sun.

"A room? It's a simple room."

There was a room about 8 tatami mats in size.

The walls, ceiling, and floor were all made of compacted earth.

There was a desk and a chair, and the walls were adorned with various types of weapons.

The most noticeable thing was a heavy stone door.

I looked up.

There was a hole from which I had fallen.

"Whoa, I fell from there? It looks like a grain of rice."

Looking closely, I could see tiny white lights smaller than a grain of rice.

"Really, I'm lucky to be alive, and unharmed too."

I almost cried.

That's because the bento and sports drink I bought at the convenience store were floating down gently.

I caught them and turned back to the room.

"This room is definitely man-made. I wonder who thought to build it here."

I placed the bag with the bento on the desk and picked up one of the swords hanging on the wall.

Hmm?

Would this get me arrested for violating the Sword and Firearm Control Law?

And, is this really Japan?

Considering how I fell, it could be Brazil.

Or maybe London.

The magic-like force earlier felt like something straight out of "Welcome to Hogwarts School of Witchcraft and Wizardry."

Hey, hey, hey, don't escape reality, me.

You need to face the facts.

So, I carefully examined the most suspicious door.

But it was just a stone door with a naked, busty woman drawn on it.

I couldn't help but touch the woman, and then, as if being written, glowing letters slowly appeared.

Hmm, interesting, oh, I see.

But I couldn't understand what was written at all.

Since the letters appeared as if being written, I thought someone might be watching and spoke to the ceiling.

"Um, I can't read what's written here. Is this some kind of ancient script?"

Then, a hologram-like image of a person appeared above the letters.

It was an old, dignified man with a white beard, wearing a wrinkled white robe like an ancient god.

"Ah, hello."

『――――』

"Can you understand me?"

『Hello, I understand. I know this must be confusing, but please listen calmly.』

"I can understand you. Actually, I'm pretty calm. So, where am I?"

『I am Louis. I am the king of a country in a world different from yours. I will start by explaining this, so please listen. It might be a bit long, so you might want to sit in that chair.』

"Wait, can you tell me where I am first? Is this Japan? Brazil? London? Or maybe another world?"

『――――』

Ah, I get it, I thought it was a bit off, but this is a recording.

So, I sat in the chair as the old man suggested.

I'm a bit hungry, so I'll eat a little of the bento.

I only have this much food, so I'll eat it slowly.

『Well, are you ready? What I'm about to say is the same as what's written on that door. I left this recording in case you couldn't read the text, so please listen if you can't read it.』

Thank you for the late answer.

But I wish you had told me a bit earlier.

『First, as I mentioned, I am the king of a world different from yours. In our world, there are creatures called monsters that are different from ordinary animals. They possess great power and can easily kill ordinary people. To counter this, our ancestors prayed to the gods and obtained the power to fight against the monsters. This power is called skills and magic. For 800 years, we fought against the monsters, but they evolved to use skills and magic as well. They even started creating dungeons. This is the situation in our world and the situation you are in now. Please take a moment to understand this.』

Hmm, I see, so it's not about Hogwarts School of Witchcraft and Wizardry.

It's more like a fantasy world.

A dungeon.

...So, the other side of this door is probably a dungeon, right?

『Well, let's continue. In these dungeons, extremely powerful monsters began to appear. These monsters would leave the dungeons after a certain period. We tried to stop them by conquering the dungeons, but there were too many of them. If this continues, humanity will be extinct in a few decades. That's when, with the proposal of our great sage, we decided to connect the entrances of the dungeons to another world and ask for help. This is the entrance to the dungeon.』

Wow, I was right.

『So, we are asking for your help to conquer the dungeon. Of course, you would die easily as a normal human, so the gods have granted you and your fellow travelers the same skills and magic as us, tailored to your abilities. We ask you to use these to save our world. Please, save our world.』

With that, the old man bowed deeply.

So, I'm in a dungeon, but I'm still in Japan, right?

That's a relief.

But I can't climb back up, so I have to conquer the dungeon!

And, I'm interested in skills and magic as a guy.

But I don't want to die.

And I don't like pain.

『Oh, I almost forgot.』

The old man spoke again with a silly face.

『Only the first person to hear this message can hear what I'm about to say. I am truly grateful to you. Without you opening this dungeon door, nothing would have started. As a token of my gratitude, I will give you one skill and one magic. Please accept them. May your adventure be blessed.』

Then, the hologram disappeared.

It seems I received something, but how do I check it?

This old man didn't give me any important information.

He only gave me background information and then threw me off a cliff.

If he were here, I would have complained, but I'm alone.

Can I take all these weapons?

Otherwise, I'd have to fight bare-handed, which would be painful.

I picked up a katana-like weapon from the wall.

"Whoa, I can't use this. The center of gravity is too far from my body, making it hard to handle."

I put it back and picked up a smaller sword.

"Ah, this one I can use. I want another one of this size."

Looking around, I couldn't find any similar weapons.

Ugh, my dream of dual-wielding...

I decided to take a long spear next.

"It's long, but I can't swing it around in a cave. Still, it's better than a sword."

So, I stood in front of the door with the small sword, spear, and bento bag.

Then I realized,

"Ah, this bento is really in the way. I need a bag to store things."

As I thought this, the bento and sports drink in my hand disappeared.

"Hey, wait a minute. Where did they go? Hey, give them back, they're my precious food... If I had known, I would have eaten them all!!"

I ended up making a perfect "orz" pose.

Then, in front of me,

【Contents】

Convenience Store Bento "Salmon" ×1

Sports Drink 500ml ×1

appeared.

"Whoa, that's a surprise. What is this? Did I lose my food?"

I realized something.

I'm not a dull protagonist!

This must be an item box!

"Come on, appear! 'Item Box Open!!'"

As expected, a menu-like screen appeared in front of me.

When I pressed the "Bento ×1" on the screen, the bento suddenly appeared in front of me.

"Food revival!!"

Wow, what a great discovery.

I wonder how much this can hold.

I don't know, but I might as well take all the weapons here.

They'll just rust if they stay here, so I'll take them.

So, I put away the weapons one by one, and they all fit.

While I was at it, I took the chair and desk as well.

Here's the start of my glamorous dungeon life!

Wait, hold on.

I know about the item box.

Can I somehow check my skills and magic?

"Skill Open!"

"Tell me my skills!"

Nothing happened.

Then...

"Status Open!"

A different screen from the item box appeared in front of me.

【Status】

Name: Amikawa Hotaru

Title: Number 1

Skills: Otherworldly Appraisal Lv.1

Item Box Lv.max

Magic: Water Magic Lv.4

Equipment: Beginner's Wakizashi

Well, I'm glad I know, but it's not what I expected...

There's no status parameters, race, level, or job?

Phew, I need to switch gears.

The first thing I learned is that I can use water magic.

I can finally use magic!

When I pressed the water magic section, a list of available spells appeared.

【Water Magic】

Water Sorcerer

Water Jet

Water Floor

Water Bullet

Water Bind

I tried them all, but I could only use the first two, probably due to some kind of MP or stamina.

Water Sorcerer was a spell that produced a small amount of water, which wouldn't be useful in battle but tasted great as drinking water. I won't have to worry about water.

Water Jet was a spell that shot out about a liter of water with the force of a hose.

The other three didn't respond when I tried to use them.

Alright, it's decided.

My weapons are Water Jet and a large collection of weapons.

I'll do my best with these.

I grabbed the heavy stone door.

"AAAAHHHHH!!!"

I knew it would be heavy, but it was so heavy it didn't want to open.

After a lot of effort using the principle of the lever, I finally managed to open it.