Lin Beixing, who has been giving up herself in order to follow love, is extremely sad because of her boyfriend's cheating. When packing up items related to her ex-boyfriend, she accidentally deletes text messages in her old mobile phone and frequently travels back to high school, but she is always dragged back to the real world whenever she is in the best moment. After several explorations, Lin Beixing found that the key to crossing was related to Zhang Wansen, so she decided to save Zhang Wansen and started a wonderful story of time-space redemption and mutual growth.