The film is adapted from the novel of the same name by Kei Oishi, a writer who specializes in taboo themes. It tells the story of Naoto Mitsui, who is not valued by anyone, and meets the girl who first called his name in his school days again after eleven years, but the other person seems like a different person. Mitsui hides under her bed to monitor her, and the madness of love accelerates his rampage.