Triad leader Chiu (Ray Lui) calls up a meeting hoping to find someone willing to adopt an abandoned male infant he picked up in Temple Street. During the meeting, nobody was able to stop the infant from crying until it was passed to a servant's arms. He is Tong Chau Sui (Ng Man-tat), who is chosen as the adoptive father of the infant. Because there were twelve people in the meeting and everyone were the infant's godparents, Chiu names the infant Tong Sap Yee (lit. "Tong Twelve"), whom everyone calls as "Prince Twelve".

On the surface, Prince Twelve (Andy Lau) seems like a favored person, but down his heart, he is lonelier than everyone else. His adoptive father Chau Sui is a worker of a mahjong house in Temple Street while his adoptive mother Phoenix (Deanie Ip) is an ex-prostitute who claims to have abandoned his son in Temple Street on the same day Twelve was abandoned, and thus, treats Prince Twelve as her biological son.

The renowned Prince Twelve has a rival named Lap Ling (Chin Ho), who is the leader of the Kwoon Chung Gang and a person more terrible than a devil. One day, Prince Twelve meets a girl who came preaching at Temple Street named Teresa (Joey Wong). From the first moment he looked at her, he fell in love with her.