Ordinary Person × Modern Dungeon × Summer Vacation Life = Rise to Success!? 〜A Private Dungeon Was Made at the Remains of a Secret Base From Childhood〜

Everyday Summer Vacation. And Before I Knew it, I Was the Strongest & Rich! 

A world where dungeons suddenly appeared everywhere. 

Even here in Japan was no exception. And in each prefecture, several large dungeons exist. 

In the dungeons, magic stones are found, an unknown energy source. And materials never seen before could be harvested. Those with talent all rushed to become [Explorers] and built up wealth. 

Meanwhile, the protagonist, Natsume Koichi, did not have any remarkable talent recognized even in the dungeon aptitude national test. And while still admiring explorers, he spent his days working as a corporate slave. 

Moreover, perhaps because of his clumsy personality bringing misfortune, he ended up getting fired from his company. 

At the bottom of despair, he returned to his family home. He then casually peeked into the secret base in the mountain that was his childhood playground. But there, a dungeon gate swaying and writhing had been born. 

Inside the dungeon gate, the summer vacation mountain spread out, where cries of cicadas poured down. Even though it was winter outside, the sense of seasons seemed bugged. 

According to an inspection by the authorities, the dungeon was certified as “just an empty space” with no monsters or items. But in truth, it was not like that――. 

Through self-training in the private dungeon, and repeatedly challenging the dungeons in the city areas, Natsume becomes famous and gains wealth.