No money, no hobbies, no girlfriend... Masao, who was living by inertia, one day ended up treating an injured succubus named Mei at his home. Hearing her story, he learns that Mei, a low-ranking demon, forced herself to come to the human world and was unable to return to the demon world. Feeling sympathy, Masao decides to help Mei accumulate magical power, but the way to do so is to have creampie sex...!?