Zhou Xingxing (played by Stephen Chow) is the captain of the Flying Tigers. He was ordered to go to St. Yuqiang Middle School as an undercover agent to find the police superintendent's gun that was stolen during a visit. Zhou Xingxing accepted the task even though he was helpless. He quickly adapted to school life. His kung fu skills were also supported by many students in the school. Zhou Xingxing also took the opportunity to investigate the missing gun case. Another undercover police officer Cao Dahua (played by Ng Man-tat) also participated in the case. In the end, he worked together with his classmates to help Zhou Xingxing solve a large-scale arms trafficking case.