At the moment when Sensei, a celebrated author, is about to realize his lifelong dream of committing a double suicide with his beloved Sacchan, he gets struck by a truck and is transported to another world. There, the local priestess Annette assigns him the daunting task of defeating the demon king, but Sensei rejects this mission and instead focuses on searching for Sacchan, hoping she has also been brought to this new world.
During his travels, Sensei accidentally saves the martial artist Tama from a dangerous situation, prompting Tama to join him out of gratitude. Not long after, Annette also decides to travel with them, drawn by Sensei’s captivating personality and determined to protect his life.
As the unusual group journeys through treacherous, monster-infested territories, they begin to realize that the real threats to the world’s peace may come from humans themselves, and that Sensei might be uniquely suited to prevent these dangers.