The story takes place in the southern coastal city of Zengjiang. This economically developed city has experienced drastic changes in the times from the late 20th century to the 21st century. Eight-year-old Lin Huaizhi returned to his parents from the countryside and met Xia Zi, a girl of the same age, in an old-fashioned tube building. The childhood friendship took root in the interactions between his parents' generation. When he was in elementary school, the Lin family suddenly encountered a marital crisis. His father cheated and the family was broken up. After his mother left home, Lin Huaizhi was bullied at school. In order to protect Xia Zi, he chose to distance himself. After his parents divorced in junior high school, Lin Huaizhi moved to Sioux City with his mother, where he met two sisters, Bai Lu and Bai Shuang. However, he experienced separation again because of the divorce of Bai's parents. Xia Zi, who reunited in high school, spent her youth with him, but unexpectedly disappeared after the college entrance examination. After entering Sioux City University, Lin Huaizhi and Bai Lu fell in love again and got married after graduation. When Xia Zi suddenly returns with her children, the fate of the three people is intertwined in the tide of the times, reflecting the changes in different generations' perceptions of marriage, neighborhoods and emotions.
