The school club activity is about to take place, and the equipment prepared suddenly breaks down. Fang Li, who has extraordinary talent in mechanical design and production, is assigned to come to the rescue. By chance, she meets Lin Yi, the president who is one year older than herself. As time went by, Fang Li felt that Lin Yi in front of her seemed to have the same experience as herself thirteen years ago. Just when Fang Li showed off her cards to Lin Yi and wanted to seek help from him, Lin Yi actually lost his memory...