Life and death are separated, and beauty is short-lived. After bidding farewell to her sister who was destined to be separated from her, Yuan Zhihua (played by Zhou Xun) embarked on her journey home with a slightly lonely mood, her husband and her sister's son Chenchen. Before leaving, she received an invitation letter from her niece Mumu (played by Deng Enxi), which was an invitation to her sister Yuan Zhinan's junior high school reunion. In the gathering environment of old friends who had reunited after a long absence, Zhihua, who was regarded as Zhinan by everyone, could not frankly tell the fact that her sister had passed away. She chose to leave first, but on the way she reunited with the sisters' old acquaintance Yin Chuan (played by Qin Hao). After that, Zhihua wrote a letter to Yin Chuan in the name of her sister to relive the memories of her youth. At the same time, Mumu and Zhihua's daughter Saran (played by Zhang Zifeng), who stayed in their hometown, received a letter from Yin Chuan. Out of curiosity about their mother's past, they wrote a reply with childish strokes. In the noisy and hurried electronic age, two generations are separated into three places, redrawing their past years and lives...