Yin (Stephen Chow), a fast food worker, met Ali (Christy Chung) who was learning Japanese karate at a martial arts training hall while delivering fast food one day, and fell in love with her at first sight. After being humiliated by the martial arts coach Lam Kwok-bun who also liked Ali, Yin, who felt too weak, decided to take Uncle Tat (Ng Man-tat), who called himself the "Devil Muscle Man", as his teacher. At first, Uncle Tat only wanted to cheat Yin's money, but was finally moved by her kindness and persistence and began to teach her ancient Chinese boxing. Ali was intercepted by a bad guy, and Yin put on a Garfield mask to rescue her. In a hurry, he rolled down from the high platform holding the gangster, but he created the "Invincible Hot Wheels", but Lam Kwok-bun took the credit for it later. In order to prove his strength, Yin signed up for a fighting competition to duel with Lam Kwok-bun, hoping to win Ali's heart again.