Saitou gets a new life as an adventurer in another world. He joins a party with armored warrior Raelza, the fairy Lafanpan, and the wizard Morlock. As he begins his adventures, he makes full use of the skills he cultivated in his last life as a handyman.

A demon king has appeared in a neighboring kingdom and the king has to figure out how to deal with it. Meanwhile, Saitou makes a mistake which sets off a trap that sends him to one of the lower levels of the dungeon.