 Ai, a young prostitute specializing in costume fantasy, decides to have some fun by dressing as a police officer and questioning people around the site of a recent murder. She is invited to lunch at one house, only to discover that her host is the murderer, he is holding a family of three as his prisoners, and now Ai is his fourth. As time goes by, the killer s insanity begins to rub off on Ai and the family, until they begin to share in his warped view of the world.