Etymology and distribution of 正口.

Masaguchi 【正口】^{レベル1
Very rare}  The Japanese surnames etymology dictionary.

Kagoshima-ken , Miyazaki-ken , Hyougo-ken . Creation . From the favorable "Yoshi", "Sakari". Kagoshima-ken Aira-shi From Yoshimori gate of the gate division system which was in Edo era in Nishigomeka. Miyazaki-ken Miyakonojou-shi Tell him that he was engaged in agriculture in Mikawa-cho. Estimated in the Edo period. Kagawa-ken Takamatsu-shi Tamamo-cho was in the Edo period in the Sanuki Takamatsu clan in the Clan office. There is Yoshinori in the name of the man.

※ Ishikawa-ken Suzu-shi In Otani Town tells that it is the descendant of Heijutsu, the principal of the Heian period. 平 Taira reference.