The Summer in Nanjing.

He Nanjing, a veteran bus driver with a spotless 15-year safety record, faces mounting pressure due to infertility in his marriage with his wife, Wei Li. Their relationship begins to unravel. During their separation, He Nanjing unexpectedly meets a young boy named Tongtong, who is being raised by a single parent. As He cares for Tongtong and builds a bond with him, both he and Wei Li gradually rediscover the meaning of love, family, and what truly matters in life.