汝、現代ダンジョンに希望を持つべからず, Thou Shalt Not Have Hope in Modern Dungeons, Nanji, Gendai Dan John Ni Kibo Wo Motsubekarazu

Japan, where modern Dungeons have become commonplace. Haruo Irikawa, who works for a Black Company, purchases a detached house at an exceptional price from a junior in college. However, a Dungeon has appeared on the grounds of that house, and Haruo is forced by law to manage it. Quitting his Black Company, he challenges even more Black Dungeon management——!!