Former black company employee, Jirou 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 to complete the dungeon that even the hero would not be able to clear. He has a hot dark elf boss who has an amazing ability "Magic resistance." The new life of our main character starts!