There is a mysterious "Time Exchange Bureau" in Qingteng Middle School. Students can use their memories, expertise or emotions in exchange to gain opportunities to change the current situation. The exchange requires signing of a contract, and if you break the contract, you will face the penalty of complete erasure of memory. The existence of the exchange has been passed down from generation to generation on campus, but no one knows who its real controller is.
- Female protagonist: Lin Xiaoman, a transfer student in the second year of high school. She is good at writing. Due to her parents' divorce, she has a withdrawn personality and carries around her old notebook left by her mother.
- Male protagonist: Lu Chenzhou, a high school student in the third year of high school and captain of the school debate team. On the surface, he is cold and venomous, but in fact, he is closed off due to the accidental death of his younger brother. He has a rare "memory retrospective" ability.
- Second Male: Xu Zhiyao, a gentle and cheerful class monitor, Lin Xiaoman's junior high school classmate, runs a used bookstore at home, and secretly investigates the secrets of the exchange bureau
- Second female: Su Qing, school beauty and student union president. Her family controls the school resources. In order to retain Lu Chenzhou, she made many transactions with the exchange bureau and gradually lost herself.
Purpose: campus love