The scum of the police, San Ge (Lin Zhengying), swept away nearly 100 million yuan worth of jewelry and fled to Japan. Although two detectives, Ji Gu Cao (Jackie Chan) and Du Jiao Jin (Yuen Biao), followed and pursued him, San Ge was still rescued by the Japanese underworld leader Matsumoto, and Ji Gu Cao and the two were also in crisis. Due to the restrictions of public image, the Hong Kong police are reluctant to use local police forces. Inspector Cao (Cao Dahua) found the criminal Partridge (Sammo Hung) who was serving his sentence, hoping to use his power to extradite San Ge back to Hong Kong. Partridge then gathered friends from the orphanage, American Ginseng (Qin Xianglin), Rhinoceros Skin (Feng Cuifan), Dashengdi (Ng Yaohan) and Momordica (Eric Tsang). Under the coercion and inducement of Inspector Cao, the five jokes and the female detective, Bawanghua, embarked on a journey to Japan...