Kinji Ninomiya is determined to become a rich NEET and by investing into a real estate empire becomes wealthy without ever having to work. A portal suddenly transports him to the world of Amuria populated by demi-humans. Here the Age of Heroes is over and the dungeons they once explored are mined by modern corporations for the ore Demonite. Kinji is forced to become a miner but soon incurs enormous debts. He befriends Wanibe, a crocodile demi-human and volunteers to prospect deeper in the dungeon where monsters are more dangerous but Demonite is plentiful. He reveals to Wanibe he discovered a secret entrance to the third level...