Paper Cranes on a Rainy Day

During the rainy season at Yulan Middle School, Lin Xia finds a soaked blue paper crane at the school gate. When her fingertips touch the paper, she feels a sadness that isn't her own. The crane awakens only in natural rain, pointing toward lost objects trapped by regret and leading her to the silent boy Zhou Yan. Zhou Yan has waited four years for his missing sister and folded 407 paper cranes. To find lost belongings, missing memories, and people erased from the records, Lin Xia, Zhou Yan, and Xu Qing form the Lost and Found Club. But when a door appears in the old library corridor during a rainstorm, Lin Xia discovers that the truth she is searching for is searching for her, too. Someone is trapped in the rain, waiting for them to remember.