Jing Koo or Koo Jing (Stephen Chow) is a self-proclaimed Trick Expert who has a wide range of tricks at his disposal, including many practical jokes and some more serious tricks which are even capable of driving a person insane. He uses such tricks to accomplish whatever requests his clients give him. When he is hired by Macky Kam (Waise Lee) to ruin the relationship between Che Man-kit (Andy Lau), an honest employee who works at the same company as Macky, and Lucy Ching (Rosamund Kwan), the company president’s daughter whom Macky is romantically interested in, Jing sets up an act to get in the Che household as Kit’s long lost younger brother Che Man-jing. Kit is suspicious of Jing at first, but is later convinced that Jing really is his brother and decides to treat him better. He gets Jing to work in the same company and introduces him to Lucy and her friend, Banana Fung (Chingmy Yau), who later on becomes interested in him.