Among the hundreds of surnames, there is no one with the surname Zi. The surname Zi comes from the surname Gui. From "Xi Xing Lu".
The original meaning of zi is elephant trunk. Shun's younger brother was an elephant, and training elephants in the tribe was a profession. Xiang's descendants have the surname Zi. "Xi Xing Lu" says: "Zi's surname comes after Ji's surname", while "Shiben" says: "Zi's surname comes after Zi." I don't know the basis for this.
Extended information
Distribution of self-surnames: The age of appearance is unknown. During the Hongwu period of the Ming Dynasty, it was moved from Taiyuan, Shanxi to the southeast of Tengzhou, Shandong. It was named Zijiazhuang. It is now called Zizhuang Village. There are hundreds of self-surnames. Man, this has been passed down to twenty-eight generations. It is also widely distributed in other areas of the province, and Jiangsu also has this surname.
Hebei Shangyi, Fuping, Huolu, Weichang, Henan Lushi, Shandong Pingdu, Shanxi Taiyuan, Changzhi, Hubei Laohekou, Hunan Lengshuijiang, Yunnan Dali, Lincang, Pu'er, Baoshan, It is distributed in Nujiang, Xishuangbanna and other places. The Han, Bai, Yi and Lisu people have this surname.
Baidu Encyclopedia - Surname