He Xiaoyu is like a girl from a distant planet. She has been out of date for many years, and the innocence in her heart has not improved much because of it. She is the first college student in the village to pass the exam. In the new and unfamiliar environment of the university, she is incompatible with others, whether she is Cinderella or a country bumpkin, but there is one thing that God particularly favors her. She has the opportunity to realize her dream - by writing homework for a teacher who is also a stranger and has no knowledge of her.
In each of these assignments, she was full of curiosity and hope, and sometimes she would get upset and get angry.
She is a growing girl with young stories and worries waiting for secrets to sprout. A group of friends who spent their youth together, never getting close to the girl, but the only one who cared about her was the bright senior, and the mysterious teacher who silently accompanied her behind her and gave her strength. These beautiful music notes are intertwined into the ding-ding-dong that belongs to her and Xiaoyu.