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.

When the wire cutters that Saitou brought with him from his last life break, he asks a dwarf named Dohnbain to fix them. Later, when Saitou can’t stop wondering about the golem they defeated, he and the rest of the party head into the great labyrinth.

Adventurers from all over the kingdom flock to the new area that Saitou discovered. Saitou wants to go and investigate the curiosity that first lead to the discovery. Meanwhile, the king orders his allies to retrieve a hidden treasure from the new area.

Kisurugi and his demon allies swoop down on Saitou and the others once again! Kisurugi has been assassinating the strongest adventurers in order to obtain the hidden treasure of a mage who can control time, but his reasons aren’t what anyone expects.

The dark spirit attacks Saitou and the others with powerful light magic. Even working together, it’s all the skilled adventurers can do to defend themselves. Then Saitou suggests a measure that could turn the seemingly hopeless situation around.

Morlock has magically stopped time, but he's completely forgotten what he's supposed to be doing! However, Saitou has anticipated even that! Then, just as Morlock is about to attack, someone else's memories flood into him.

There is a way to save the witch, Rahvella, from her curse, but will Kisurugi truly be willing to pay the price? And when the method of Saitou’s arrival in this world is discovered, will it change things between him and the others?

When Saitou and the others learn that their friend has died and been buried in the wastelands at the edge of town, they gamble on a slim hope and spring into action. Meanwhile, unbeknownst to them, Morlock has had an unusual spell cast on him.

As Morlock and Saitou talk about Raelza, the demon dog attacks! Raelza and Lafanpan arrive to find their friends at a clear disadvantage. Then, the demon dog’s master, a twin-headed demon with strength on par with a demon king, appears before them.

The double-headed demon has been stuck with magic powerful enough to fell a dragon. In the aftermath, Morlock feels sympathy for the demon dog and says he wants to try to save it. But then, Saitou and the others are struck by a surprise attack!