Zuo Jingxuan is Zuo Zhiyuan's grandfather. His father Zuo Weiyuan and mother Qian both passed away when Zhiyuan was one and a half years old. He grew up with his grandfather. Yu Shichan was Zuo Jingxuan's close friend. Yu Shichan sold the house in his hometown, transferred the house in the courtyard in the city, bought a piece of land in the town close to the school district, built a small courtyard, and invited Zuo Jingxuan to stay there for a long time. Zuo Jingxuan did not want to live and eat for free, so he used his Longmen recipes and half his life savings to open a restaurant, and invited Yu Shichan to join in the joint operation. The name of the restaurant was called Longmen Shibawei.