Upon transferring to Xingcheng Mingli High School, Shen Xingruo lived under the same roof as Lu Xingyan and attended the same class. Over the course of a year and a half, their relationship evolved from initial animosity to gradually developing feelings for each other. Years later, they are reunited through, "Go Back Lover," a reality show for exes, first love, and the nostalgia of youth between high school friends.