Is there any reality of the four restaurants under Zhengyangmen?

No. The four restaurants under Zhengyang Gate are: Tea Fragrance, Drinking, Gathering Friends, and Returning Downstairs. In real life, there are no these four restaurants. The male protagonist Han Chunming, his master Mr. Guan, and three good friends in Beijing express their friendship by using four tea cups, each representing each person. Han Chunming collected these four tea cups and named the four restaurants he opened after these four names.