27-year-old girl Zhong Xiaoxiao has been living an ordinary and busy life. At a class reunion, she wanted to give the DV recording her youth to her secret crush Xu Yang, but the moment the DV was opened, she returned to the age of 17. As Zhong Xiaoxiao's white moonlight, Xu Yang, played by Fang Xiaodong, was a cold and arrogant academic master during his student days, often exuding a cold temperament that kept people at a distance. What made Zhong Xiaoxiao collapse more than returning to the age of 17 was that her time often jumped suddenly. After many experiments, she found out that only when she stayed within a certain range of Xu Yang could she have a normal flow of time, so she also discovered the unknown side of Xu Yang. By chance, Xu Yang moved into Zhong Xiaoxiao's house. As the two got closer, many ridiculous stories happened...