The story takes place during the reign of Emperor Renzong of the Northern Song Dynasty. Bao Zheng (Liang Guanhua), the prefect of Kaifeng, enforces the law impartially and is not afraid of the powerful. As a result, he is deeply envied by a group of evil people headed by Master Pang. During the investigation of the Black Tiger Village, Bao Daren, who was in danger, was rescued by the knight Zhan Zhao (Yan Yikuan). After returning to the capital, Zhan Xiongfei showed his unique skills in front of the emperor, and was eventually given the title of "Imperial Cat" by the emperor, but this caused new troubles. It is said that there are five knights living on Xiankong Island far away from the capital. They are Lu Fang (He Yu), the Sky Rat, Han Zhang (Wang Daqi), the Mountain Rat, Xu Qing (Xie Ning), the River Rat, Jiang Ping (Wang Maolei), and the Golden Rat Bai Yutang (Chen Xiao). They have unique skills and are collectively known as the "Five Rats". The arrogant Bai Yutang resented Zhan Zhao's nickname of Imperial Cat and insisted on going to Beijing to compete with him. This led to the legendary story of "Five Rats in Tokyo"... This film is adapted from the classic novel "Three Heroes and Five Gallants".