The story takes place in 2018. After 15-year-old girl Su Yushi had a crush on the boy she liked for a whole semester, she finally couldn't help but try her best to enter his world, but the boy wanted to sworn brother and sister with her? ! Unwilling to do so, Su Yushi tried every opportunity to express her love to her "brother", but failed repeatedly. Can Su Yushi successfully break the "brother-sister relationship" and be with the boy she likes?
Concept: Regarding us and the people we love, the best ending may not happen at the end, but hidden in the long youth.