Mike, a policeman, is a showy rich kid who often spends his father's money in solving cases. Although he has solved countless cases, he cannot win the recognition of his colleagues in the police station and his girlfriend Lisa, and is annoyingly called "Playboy Policeman" by everyone. After finding out that Lisa is closely related with Lin亨, a policeman from mainland, Mike feels jealous, fights with Lin Hen, and even gets suspended. However, Lin亨 does not care about these. His purpose of coming to Hong Kong is to investigate the cause of his brother's death.