Fallon Zhu (Donnie Yen) is a Hong Kong police officer. In the eyes of the public, he is an agile fighter with a high crime detection rate, a police role-model. Unfortunately, his fiancée Chloe (Niki Chow) dumps him before their marriage. Heartbroken, he indulges in food to relieve his pain. In half a year’s time, his endless intemperance transforms him into a 200+ pounds being.

 

His superior, Superintendent Huang (Louis Cheung), puts him in charge of a routine mission to escort a suspect to Japan, so he can lose some weight and pressure as a side-plan. However, a series of mishaps befall him in Japan. He loses all of his belongings, and above it all, he loses the suspect in his custody when he handing over him to the Japanese police Yuzo Endo (Naoto Takenaka). His luck turns when he encounters another Hong Kong citizen Thor (Wong Jing), and the hot pot restaurant owner Charisma (Teresa Mo), who help him out of his ordeal.

 

But the respite is short-lived, his suspect suffers a mysterious death. In order to complete his mission, Fallon and Thor join forces to solve the puzzle. To everyone’s dismay, troubles continue to snowball, even the people around Fallon are being dragged into the mess. Fallon is determined to uproot the gang, regardless.