Hangzhou youth Xu Tian, motherless since childhood, believes fervently in parallel worlds. When he passes Bei Jing's near-identical stranger Zhou Tong on the street, he becomes obsessed with finding him. Through a blind date, he meets pragmatic Shi Diandian, who readily joins his search. But fate twists when Zhou Tong crashes en route to his girlfriend Wen Xiaoyao's performance. On this pivotal day, both couples' lives fracture. As Xu Tian and Shi Diandian navigate grief and unexpected connection, they slowly mend each other's emotional wounds. Meanwhile, Wen Xiaoyao channels heartbreak into artistry, ascending as a star ballerina, her career-defining moment born from reciprocal love with Zhou Tong.