In a marriage that exists in name only, Su Nianwan has hidden her grievances for eight years. On the day she asks for a divorce, her husband's friend, Shen Zhiyu, offers her a black umbrella and reveals a secret love he has kept hidden for ten years. A high school classmate who sat behind her, a soda can ring, and unanswered late-night calls—her forgotten youth has, all along, been quietly treasured by someone. When her old relationship finally falls apart, she realizes that true love is not about draining or possessing someone, but about respect, protection, and letting them be happy. After saying goodbye to the wrong person, can she embrace a new life of her own?