Lin Xiao, Gu Li, Nan Xiang, Tang Wanru - these four best friends, after waving goodbye to their school campus and entering the workforce, they are faced with various challenges in their life: friendship, love, and career. Together, they become lost in life, having long forgotten their past courage.
In the film series finale, Lily finds herself near financial ruin because of the debts left behind by her father, all while battling a newly diagnosed cancer. Too proud to seek solace from anyone around her, Lily sets off a chain of self-destructive events that lead to her estrangement from best friends Lin Xiao, Nan Xiang, and Ruby.
