Higuchi Kotarou was just an ordinary sixth-grader until he acquired a new next-door neighbor: an incredibly energetic angel named Misha, who has dedicated her life to making Kotarou happy. And if that weren't enough, Misha shares her home with an even stranger roommate—a kind-hearted demon named Shia and her mysterious black cat, Nyaa. If Kotarou's life at home is this bizarre, what could it possibly be like at school?!