16-Year-old Lin Wanxing moved from Jiangcheng to Su's house in Huacheng due to family changes. When they first met, Su Yu, whose jersey was soaked in sweat, glanced at her casually, but stopped when he saw the small bamboo lamp on the suitcase. From then on, the exclusive position on the back seat of the bicycle, the sweet and sour pork ribs on the canteen plate for her, and the warmth of her wrists when she climbed over the railings and ran with her at the gym, made her heartbeat secretly hide under the label of "brother and sister".