Secrets of Shanghai tells the story about Ln Bainian, an old Chinese businessman who has been living in Barcelona for more than 20 years. When he is diagnosed with a terminal illness, he returns to Shanghai to find the daughter he abandoned. There is deceived by an officer who sees a good opportunity for his girlfriend, who impersonates the daughter of the protagonist. Meanwhile, the true daughter also lives in Barcelona and the two girls become friends. From there, the relations between complicated.