Shamoto runs a small tropical fish shop. When his daughter Mitsuko is caught shoplifting at a grocery store a man named Murata steps in to settle things between the girl and the store manager. Murata also runs a tropical fish shop and he and Shamoto soon become friendly. However Murata hides many dark secrets behind his bombastic and gregarious persona.
The film is loosely based on the real life 1993 murders that became known as the ''Saitama serial murders of dog lovers.''