Etymology and distribution of 坪本.

Tsubomoto 【坪本】^{レベル4
About 600}  The Japanese surnames etymology dictionary.

Toukyou-to · Saitama-ken · Yamaguchi-ken . There is a belief in the name of a man. In the Chugoku Period, Yamaguchi-ken Hagi-shi Horiuchi was in the Edo period in the Choshu clan in the clan office during the Warring States Period. The same clan says that he was renamed from Saka surname by hiding Saka Nagato Morihiro Hidemu who was also referred to as Mamoru Mouri, a warrior of warring States era. 坂 Saka reference.