Xia Cha lives with his grandson, who has a crush on his neighbor and classmate. Two family members get into an argument and fall down the stairs. When Xia Cha wakes up, he is in his grandson’s body, and has to go to university in his stead. Unexpectedly, he and his grandson end up kissing.

Hsia Cha realizes that his soul is in his grandson’s body, and tries to set things right. Haiyuan soon notices the change, and agrees to help retrieve Zefang’s soul. Hsia Cha tries to adapt to school life, but after his original body gets cremated, he realizes he has no way back.

Xia Cha goes back to college as his grandson, confused about young people and worried he might embarass Ze Fang, and sticks close to Hai Yuan.

Hsia Cha moves in with Haiyuan to avoid Riqing’s advances. Haiyuan notices Hsia Cha becoming more and more clingy, while Hsia Cha gradually understands Haiyuan’s difficulties. At night, the two end up sharing a bed, and sparks start to develop between the two.

Hsia Cha gradually adapts to both university life and interacting with other students, but these interactions make Haiyuan jealous, making Haiyuan question what feelings he really has. An accident affects Hsia Cha, which makes Haiyuan confront his own feelings.

Hsia Cha dreams of the past and sees a red thread connecting him and Haiyuan, with Qiansui saying this could be a connection from a past life. Hsia Cha learns how to be warmer and friendlier to others, which both touches Haiyuan and makes him jealous.