Dongfang Kai, a senior in the Department of History, can edit code and play drums. He also squats beside Tanfang of the Liao and Jin ruins all day long to rub monuments. Mo Xiaohan, a student from the Department of Computer Science, came to him for the first time because the C language course was missing a semicolon. Later, she discovered that this man knew everything - course design, creative writing, graduation design, a good night in a long-distance relationship, and a key to the same city. From the encounter under the banner of the courtyard at the freshman sports meeting, to the "accidental encounter" occupying a seat in the library; from following the guard in the museum warehouse, to the two certificates collected by the monitor at the graduation ceremony. He was one year ahead of her, figured out all the secret doors in the school one year earlier, and put her into the future one year earlier. Campus, practical training, Daiso, graduation, work, proposal, wedding dress. From school uniforms to wedding dresses, it took them six years. He said: "I have been to your world before." She said: "No, you never left."
