Upon surviving an unfortunate accident on the ferry, Li Wei decides to feign amnesia and impersonate Rui Ming to escape from his financial difficulties. As Rui Ming's wife brings him home, Li Wei meets Rui Ming's children and brother, Zi Jian, Jia Wen and Rui Jie. With an interest in inventing new gadgets, Zi Jian gets Li Wei to trial his new invention, a lie-detecting watch, where Li Wei's true identity is almost leaked