【Book Release】On February 25, 2022, the fourth volume was released by Overlap Novel! If you haven't read the first to third volumes, please take this opportunity to do so! In Edogawa, Tokyo, 'Kazuhiko Ejisuke' was living a comfortable single life as a management consultant. While investigating a strange hole that appeared in his yard, he inadvertently awakens a dungeon. Soon, dungeons begin to appear worldwide, and countries start to consider how to utilize them. However, the dungeons hold a significant secret. If left unchecked, a 'Great Monster Flood' will occur in 10 years, leading to the destruction of the world. Only the protagonist, who activated the dungeon, knows this. Amid the various schemes of nations, the 40-year-old middle-aged man gathers companions to challenge the dungeons. They are later known as the 'Dungeon Busters'... *This story is a work of fiction. The characters, organizations, countries, place names, and titles mentioned are fictional and not based on real entities.