When Chen Yidu was nine years old, a brother named "Bi Laifu" suddenly appeared in the family. Laifu, who lived in Yidu's home, was born "incompatible" with Yidu. Not only did they confront each other at home, but they also fought constantly at school. At the same time, Laifu, who had just arrived, made friends with a group of friends who valued friendship and loyalty. This group of naughty boys often united to make trouble everywhere, causing headaches for the adults. With the arrival of the college entrance examination, the children who grew up together went their separate ways. Laifu and Yidu also began to face their work, love, and life. In 1998, the automobile industry developed rapidly, and the old bicycle factory was no longer prosperous. Laifu felt that the bicycle factory was the memory of several generations of them. For this feeling, he contracted the assembly workshop and attracted investment to renovate the production line. The brothers who grew up together got together again and started a new business. They used new concepts for production and management, making the old "Flying" bicycle factory young again.