You have decided to take in and foster a child, Shiori, that has been abandoned and left alone in the world. As you take in the child and try to raise it in a loving and caring home, you begin to notice strange behavior and abilities from the child, all while they grow increasingly attached to you. All soon, you come to realize that the child you have so lovingly taken in is in fact a demon, and you must navigate your newfound situation and its implications.