Li Xing surprises his high school sweetheart, QiaoQiao, with a marriage proposal. However, QiaoQiao declines the proposal, offering arguments as to why he's not ready. They make a contract to each other that if in five years neither is married, they'll marry each other.
Li Xing stays in Beijing and Qiao Qiao leaves for Shanghai.Five years later, however, Qiao Qiao gets a surprise call from Li Xing inviting her to his impending nuptials. Hearing this news, Qiao Qiao discovers that she is not willing to give up on Li Xing so she heads to Beijing in order to throw a wrench in his marriage plans.
The twisty road to their reunion is further complicated when Qiao Qiao receives a gloomy medical diagnoses. The question is who loves who and what does it mean to love someone?