In 1940s Shanghai, Sing and Bone aspire to join the Axe Gang because Sing bought a martial arts pamphlet and practised the technique but was instead beaten and humiliated when he tried to save a girl. Afterwards, he became adamant that heroes never win, and resolved to be a villain. Thus, they pretend to be Axe Gang members and eventually attract the attention of the real gang, who confront the villagers. With the help from the kung fu masters and awakening his original intention after seeing the girl he wanted to save in the past. Finally, the evil cannot defeat the good.
The director, Stephen Chow, maintains his usual approach using a funny and fast-paced method to tell a simple story. In this time, the story is about evil cannot defeat the good and reminds viewers never to forget why you started.