Second-Hand Love Letters from Time and Space

Chen Mo accidentally received an old book from 10 years ago, which contained a "love letter" written by Su Qing to the future (actually her mood diary and dream record). He tried to reply, but received a reply from the past through the bookstore's magical mailbox. The two began a pen pal conversation across time and space. Chen Mo was infected by Su Qing's enthusiasm and regained the motivation to live. He relied on the "prophet" to help her avoid some small regrets in the past, but she didn't know that the greater fate could not be changed. At the same time, Chen Mo met a girl who looked exactly like Su Qing in reality, and a huge conspiracy quietly launched.