[Rekindled Romance + Body Swap + Pure Love, Both Chaste + Personal Growth] At 28, Song Nian is forced to go back to her senior year of high school, where she runs into her best friend and her ex.
Chen Hanjin: You really remind me of someone.
Song Nian: Oh, we're relatives. It's normal to look a bit alike.
Her deskmate, Linlin: Shen Pan, what's wrong?
Song Nian, sneaking a glance at the person at the lectern: Sudden cramps.
Chen Mo: You are unbelievable.
Song Nian: I didn't know I could be this unbelievable either.
Song Nian is a 28-year-old unemployed woman nearing thirty, living at home. For reasons unknown, she swaps bodies with her younger cousin Shen Pan, who is staying at her house. The two have no choice but to continue their lives in each other's identities for the time being. On her first day at school, Song Nian discovers that her cousin's homeroom teacher is her best friend, while her physics teacher is none other than the boyfriend she broke up with four years ago.