17-Year-old Qing Ling accidentally broke the cup and book of the school president Leng Yisheng on the playground. The story begins here. Qing Ling first fainted during the exam, as if she was in another time and space, and walked back to the past that she had forgotten because of saving that person. But in the real world, after Qingling fainted, she was immediately sent to the hospital for rescue. After two days of emergency treatment, she woke up; after reviewing her past memories, will Qingling remember all the things in the past? The male protagonist in another time and space is Leng Yisheng. What is her relationship with Leng Yisheng? What is her life experience that even she doesn't know? What will Leng Yisheng do about this matter?