Etymology and distribution of 三用.

San'you 【三用】^{レベル2
About 20}  The Japanese surnames etymology dictionary.

Nagano-ken Chikuma-shi . Terrain . From the Sea. Nagano-ken of the Chikuma River in the sense that "there is this person in the shallows" by bridge and flood was dammed make it easier to cross the river at the time of the collapse of Nagano-ken Nagano-Shi Matsushiromachimatsushiro Han Agency Mr. Masuda of the lord of Matsushiro in the Edo era. Nagano-ken Chikuma-shi is based in Uekuma . In the same place, tell the descendants of the public house who came back to avoid the war. Estimated in the Warring States Period.