Star Chow (Stephen Chow) Will be kicked out of the Royal Hong Kong Police's elite Special Duties Unit (SDU). But a senior officer decides to offer him one last chance: Star needs to go under cover as students at Hong Kong at the Edinburgh High School to regain the officer's revolver that is missing. The under cover operation was created complicated when Star has been partnered with Tat - an aging, incompetent police detective (Ng Man-Tat). However, Star still manages to fall in love with Ms Ho (Cheung Man), also the school's guidance counselor, as well as interrupting a gang involved with arms-dealing.