An Ran accidentally returned to five years ago after a class reunion. In order to make up for his regrets, he decided to save the girl Sheng Xia who had died in the tragedy. As a classmate, he silently accompanies each other, tutoring her homework and facing life problems together. He also gradually discovers that this seemingly weak girl is bearing the weight of family changes alone. The two worked together to find the truth and heal each other. In the process of growing up together, they also gained their warm youth.
