異世界からの企業進出!? ～元社畜が異世界転職して成り上がる！ 勇者が攻略できない迷宮を作り上げろ～ (Manga title) (Associated Names)

Former black company employee, Jiro Tanaka leaves his job due to overwork. In his home, he founds a job recruitment template which is from another world company. The job is to test the dungeon created by the demon king. There, the days of diving into the dungeon as a “dungeon tester” were waiting for him…