At twenty-seven, Lin Zhixia is a well-regarded architectural designer, but at the peak of her career, she suffers two devastating blows: her carefully designed landmark project is maliciously altered, and her boyfriend of three years suddenly breaks up with her. After getting drunk, she accidentally touches the "Star Trail Wish Box" she made with Su Yu in high school. When she opens her eyes again, she has returned to age seventeen, to the pivotal summer when she deliberately distanced herself from Su Yu because of her insecurity.
Carrying the memories and regrets of an adult, Lin Zhixia is determined to rewrite the ending. She no longer avoids Su Yu's gaze and joins his astronomy club of her own accord. She even gathers the courage to help him finish the "Star Trail Observation Report" they left incomplete years ago. But as they spend time together, she realizes Su Yu seems to have secrets of his own: sometimes he mentions things that have yet to happen, and his eyes hold a maturity far beyond his seventeen years.
As the milestones of the college entrance exams, parting, and life-changing choices draw closer one by one, Lin Zhixia gradually understands that returning to the past is not a "cheat code," but a mirror that lets her see her true feelings clearly. When two people carrying "memories of the future" meet again in their youth, they must fight not only the misunderstandings of the past, but also the "parting" that seems destined in reality. In the end, Lin Zhixia stops obsessing over "changing the ending" and learns to embrace the present with courage. After all, the best reunion is never about going back to the past, but about falling in love with you again in the present.
