High school student Maruo Anai is suddenly summoned to another world along with his classmates. While his classmates are given powerful jobs as heroes, Maruo receives the seemingly useless job of “Hole Digger” and becomes a failed hero. Realizing he can’t be expected to shine as a hero, Maruo starts digging a hole alone only to accidentally discover a Dungeon Core. Touching it makes him a Dungeon Master! With the combined powers of Hole Digger and Dungeon Master, Maruo mass-produces cute fluffy monsters intending to enjoy a peaceful dungeon life. But somehow the dungeon he built gets perceived as a threat…