27-year-old girl Zhong Xiao Xiao has been living an ordinary and busy life. At the class reunion, she wanted to give the DV recording youth to Xu Yang, her crush, but the moment the DV was turned on, she returned to the age of 17. Zhong Xiao Xiao's crush, Xu Yang, was a high-cold academic bully when he was a student, and he often exuded a cold temperament that refused to be thousands of miles away. The thing that makes Zhong Xiao Xiao collapse even more than returning to the age of 17 is that her time often jumps suddenly. After many experiments, she found out that it turns out that only when she stays in a certain range around Xu Yang can she have a normal time flow, so she also discovered Xu Yang's unknown side. By coincidence, Xu Yang moved into Zhong Xiao Xiao's home. As the two got closer to each other, many ironic stories happened....