Identical twins are separated at birth, one becoming a streetwise mechanic, and the other an acclaimed classical concert conductor. Finally meeting in adulthood, they're mistaken for the other and entangled in each other's worlds.

Jackie Chan
as Ma Yau (John Ma) / Bok Min (Boomer)

Maggie Cheung
as Barbara

Nina Li Chi
as Tong Sum (Tammy)

Teddy Robin
as Tarzan (Tyson)

James Wong Jim
as Mr. Ma

Sylvia Chang
as Mrs. Ma

Kirk Wong Chi-Keung
as Crazy Bull

David Chiang Da-Wei
as Sgt Chiang / Hotel Security

Mabel Cheung Yuen-Ting
as Tsui

Alfred Cheung Kin-Ting
as Boss Yung