Lazy Dungeon Master (Manga) Vol. 4 (manga)

Though once the guild catches wind of this new establishment, Keima's humble abode earns itself a new name, the Cave of Greed. Later, when Haku herself stops by for a visit, she offers up some chilling information - there's another dungeon on the mountain, the Flame Cave! Can Keima avoid clashing with his neighbours or will he and his dungeon go up in smoke?!Series Overview: Masuda Keima just wants to sleep. Too bad for him, he's been pulled from sweet dreams and comfy sheets into a fantasy dungeon in another world! Not only is he charged with protecting it, but failure to do so will cost him his life.

His only guide is the personification of the Dungeon Core, Rokuko--but she's a moron who can't even figure out how to drive away a group of bandits. If Keima ever wants to get some quality shut-eye again, he'll have to take over running this dungeon himself!