Chengdu, Chung Yeung Festival. Xia Chan dreamed that she jumped from a tall building. In the noisy city and the simple illegally built houses, it seemed that she could only hear the heartbeat of herself and the life in her belly. A few years later, one summer, she changed her mind as usual. Xia Xiaomang, a 12-year-old girl holding her photo, came from afar. Xia Chan's changeable attitude left Xiao Mang at a loss as to what to do. Until she met Jiang Ai, a girl who had just grown up, which opened up another side of the city to her. In the hot summer, things became intense, and Kang Guizhen's appearance heralded the end of the summer.