Zhang Ze Yuan's first love, Huang Shi Jie dies in a car accident. In order to save Huang Shi Jie, Ze Yuan used the camera she left behind to travel through time and space, and returned to the day of the 18-year-old senior year, hoping to save her. But despite his efforts, the ending is the same, prompting him to time-travel many times until he realizes he is not the only one who has been tampering with the past.