Chapter 1: The World's Smallest Dungeon - Episode 1: A Routine with a Dungeon

—How did it come to this?

In front of him, a rare "Metal Slime" with a metallic body was trembling. Facing it was Mita Yuzuma, an ordinary second-year high school student. In his left hand, he held a flashlight, and in his right, a perfectly ordinary hammer bought from a home center.

He was in a hole in the yard, which was only about a meter deep and not even as wide as a tatami mat. Squatting like a turtle, he was locked in a stare with the Metal Slime, a situation that was far from ordinary.

The Slime's body writhed as if it were about to pounce at any moment. Why did this happen... Yuzuma tightened his grip on the hammer, his face puzzled.

A few minutes earlier—

"The government has dispatched a survey team to investigate the sinkhole that appeared near Harumichijou. It is likely a small-scale dungeon..."

"Yes, that's right. There are five dungeons in Japan, and if this is recognized as a dungeon, it will be the sixth case in two years."

"Is this something to be happy about?"

"Well, while dungeons used to have a scary image, they are now generally seen as important places for resource extraction."

"Is there a possibility that more will appear in the future?"

"Definitely. The number of civilian 'explorers' is increasing daily, and the exploration of dungeon levels will likely progress. We need to get used to this."

"Yes, thank you. We heard from Professor Hashida, an expert on dungeons. Next up, the weather. Mana-chan!"

The TV, left on, was broadcasting a mundane news report. What would have been a topic of great interest regarding dungeons in the past was now nothing out of the ordinary.

On a summer afternoon, in the air-conditioned living room of his home, Mita Yuzuma was slouching. Lying on the sofa with his smartphone, he was idly watching TV.

He had nothing particular to do, just lazing around.

With time on his hands, Yuzuma searched for videos on his smartphone.

The top video on the homepage was about a dungeon.

"Hey! Look, this is the 'White Dungeon' in Sapporo. I'm currently exploring the 18th level. There are a lot of fairy-like monsters here!"

A young man with dreadlocks was taking a selfie on a cliff. Despite being inside a cave, the surroundings were as bright as day.

Dungeons have a built-in light source, creating a scene no different from the outside. Changing the camera's direction, he captured a swarm of something flying.

At first, they looked like birds, but they were different. Approaching were semi-transparent creatures resembling Clione. They passed by the man and soared into the sky, then descended in a curve.

"Whoa, they look cute but are aggressive! But I'm not scared, just watch me."

The man pointed his five fingers at the Clione.

Light crackled at his fingertips, and thin lightning bolts shot out. The Clione that touched the lightning were electrocuted and fell to the ground one by one.

"Haha, how's my 'Lightning Magic'? Pretty cool, right? These monsters are no match for me!"

The man continued to cast his 'magic,' defeating several Clione. Then—

"Ah! Look, everyone! The monsters dropped magic gems. 'Moonstones,' worth about 1.4 million. Great, today's my lucky day!"

The video ended with the man ecstatic. It had over 1.2 million views.

"Hmph, ridiculous!"

Yuzuma felt disgusted and closed the video.

He threw his smartphone aside and lay on his back, staring at the ceiling.

It had been seven years since the appearance of dungeons. Initially, these underground labyrinths caused fear and anxiety, but they were now accepted as a major industry in society.

Even Yuzuma, who had no particular interest, had heard some rumors.

Unknown creatures in dungeons, the 'magic gems' they produce, and the magic that can be used with these gems.

People like the man in the video had emerged, making a fortune in dungeons...

"Woof woof! Woof woof woof!!"

The barking of his dog came from the yard.

"What's going on...?"

Yuzuma got up from the sofa, looking tired, and walked to the yard. His usually calm Shiba Inu, Mamezo, was barking persistently at something.

What's wrong? Wondering, Yuzuma put on his sandals on the veranda and went down to the yard.

The house was old, but the property was large, about 150 tsubo, and the yard was surprisingly spacious.

Mamezo, who was usually free to roam the backyard, was growling and staring at a spot where low shrubs were planted.

"What is it, what's wrong?"

Yuzuma walked to the shrubs, feeling exasperated.

In the scorching sun, he was annoyed. Even if something as unrealistic as a dungeon appeared, only a select few could profit from it.

People trained by large corporations.

Highly skilled individuals recognized by the government.

Popular people with sponsors.

Only they could make a profit. The world remained unfair, and nothing changed. As a completely ordinary person, he had no chance of such opportunities.

Muttering about the unchangeable reality, Yuzuma spent his days listlessly.

Until he found a strange hole behind the shrubs in the yard.