When she was 6 years old, Qi Qing was very good friends with Xu Feng and Xu Tian. During a play, Xu Feng accidentally drowned and died. Qi Qing also lost her parents in a fire. She was so sad that she lost her memory in a sudden car accident. The Xu Tian family adopted Qi Qing, who had lost her memory, and concealed the sad memories of the past. After changing her name to Xu Qing, she started a new life as Xu Tian's sister. Xu Tian silently protected Xu Qing, and the two spent their high school and college life together. During that heart-pounding youth time, they met many friends, laughed together, cried together, sweated together, and struggled together, leaving behind the most innocent memories.