Kashiwagi Kouichi recently moved into his cousin's house after the father that he barely talked to in recent years passes away. His cousins are four female siblings ranging in age from adult to a young child: Chizuru, Azusa, Kaede and Hatsune. After their parents died years ago, Kouichi's father and the girls' uncle became their guardian. Kouichi fits perfectly in the household although Kaede seems to act reserved around him. He soon starts having vivid dreams of himself as a homicidal monster. He tries to brush it off, but it gets worse every time and he starts to hear a haunting voice along with the dream. But what scares Kouichi the most is that the dreams he is having might be reality!