Seiichi Hiiragi is at the bottom of his school's social pecking order, but one day, he and his entire school are upended when everyone in the school is transported into another world. Seiichi finds himself alone and approached by a gorilla, who instead of attacking him, proposes to him. At the moment that Seiichi thinks that "I guess a gorilla is fine too," they find the Fruit of Evolution, and when they eat it, their lives are suddenly changed once again.