28-year old Liang Xia and 34 year-old Mao Liang have been together for 10 years, and living together for 5 years. Liang Xia assumes that Mao is going to propose after 10 years of being together, and had given up her dreams on becoming a painter just to stay with Mao. However she is disappointed when the diamond he had bought was for his boss, Mr. Gao's wife to earn her support in improving his design company. Her friend suggests to Liang that she should force Mao to marry her by proposing to him in public. However, the plan backfires and Mao ends up breaking up with her. The devastated Liang eats a magical chocolate, transporting her memory back to her 17-year old self. Without the worries of adulthood, she is back to her naive, optimistic self and that triggers a surge of interest in Mao, who she now refers to as “Uncle”. Things turn even more complicated when Liang Xia's first love, Yan Yan comes back into the picture.