Dungeon no Naka no Hito

Clay spends three years training as a thief and explorer strong enough to follow her father, who disappeared after reaching depths of a dungeon almost nobody else had ever seen. She retraces his path floor by floor until a battle breaks open a wall and reveals something impossible behind it: a furnished room, monsters behaving like employees, and a girl named Belle who claims to manage the dungeon itself.

Because Clay has discovered a secret no adventurer is supposed to know, Belle offers her a job inside the dungeon rather than simply sending her away. Clay suddenly moves from avoiding traps and killing monsters to hiring them, placing obstacles, maintaining corridors, and managing treasure. The strange work teaches her how the place she spent her life exploring actually functions—and may also bring her closer to discovering what happened to her father.