The person who didn't want to leave in the library, the heartbeat of looking back under the redbud flower, the secret that had been buried for nearly ten years, the two flower-like girls, Ping and Qiu, where should they go, who made the promise that made the redbud flower bloom so brilliantly, what kind of rotten heart was underneath the sweet or handsome body... In that silent autumn, a girl asked: Why don't you come and play with me?