Gu Yu, who graduated from high school, is about to enter a new stage of life, but how can he forget the last period of his youth that he spent in an exam-oriented education? At that time, there were too many things that I couldn't understand, too many things that were elusive, and too many things that I couldn't bear. Gu Yu, a freshman in college, and Gu Yu, a freshman in junior high school, both silently moved forward on the preset trajectory of life. One day, she discovered that youth has echoes.