Etymology and distribution of 貞友.

Sadatomo 【貞友】^{レベル3
About 130}  The Japanese surnames etymology dictionary.

Shizuoka-ken , Hyougo-ken , Tochigi-ken .

① Topography . From the white waterfall. Shizuoka - ken Shimada - shi In Kawane - machi Arori, tell the descendant of the Yin Yang teacher who came from 810 to 824 (Hongdin - year). Tochigi-ken Mooka-shi It was in Edo period on Higashi Ojima. According to Uesugi Kenshin, who is a warrior of warring States in the same place, tells Shizuoka-ken that he came from Niigata-ken Jouetsu-shi under the name pattern and resides. Okayama-ken Tsuyama-shi Yamashita was in the Edo period in the Tsuyama clan of the clan office.

② Kumamoto-ken Ashikita-gun Ashikita-machi birth of Shiraki. A place name with a record since the Edo period. I used Shiraki's "White". It is distributed in the same place.