Runaway Sweetheart Xu Lingna idolizes sprinting champion Han Fei. When he leaves the track for personal reasons, she disguises herself as a boy and enrolls at his school under the name of her late brother, Xu Lei, hoping to encourage him to return to racing. Before long, Han Fei discovers that Lingna is a girl. She then uses her natural advantages as a girl to inspire him, and after spending some time together, their feelings for each other quickly grow. Their classmate Chai Ge is a rough-and-tumble guy, and he develops unusual feelings for the delicate-looking "boy" Lingna. Playboy Jiang Chao is badly hurt by his unrequited love for Han Fei's ex-girlfriend, Bei Rui, while Bei Rui believes Han Fei still loves her.
