Layar-21 – Ni Ni stars as Liang Xia, a 28 year old woman who only dreams of marrying her boyfriend of ten years Mao Liang (Wallace Huo). However, Mao Liang is preoccupied with company matters, and couldn’t care less about marriage. Unfortunately Liang Xia’s surprise proposal to Mao Liang at her best friend’s (Ma Su) wedding fails, and Mao Liang walks out on her after a decade long relationship.
Humiliated and inconsolable, Liang Xia takes a bite from a magical chocolate, and discovers her twenty something body is now controlled by her seventeen year old mind. Armed with the maturity of a teenager, Liang Xia decides to live up her life, and gets into a love triangle with ex-boyfriend Mao Liang and rebellious youth Yan Yan (Darren Wang Dalu).