Su Nian transferred to Qingjiang No. 1 Middle School due to the death of his father, and was healed by Lin Qingye's sunshine and tenderness. The two got closer to each other in friendship and studies. Lin Qingye guarded this relationship with 100 unsent love letters, but due to Chen Qian's intervention and misunderstandings, they parted ways after the college entrance examination; Lin Qingye enlisted in the army due to family pressure and despair for Su Nian, and Su Nian left home after being admitted to the normal school. The two separated with regret and resentment. Fifteen years later, Su Nian accidentally discovered a yellowed copy of "Selected Poems of Haizi" in a second-hand bookstore - it was a book that Lin Qingye had lent her. There was an unread love letter on it. The two reconnected, but they could not look back in their respective marriages. Su Nian and Lin Qingye used a youth to "pay tribute to all Bai Yueguang and the regrets of youth". They did not reconcile easily, and only gave a restrained and decent farewell: no cheating, no divorce, only a meeting in the late autumn evening, and they only said "Are you okay" to each other.
