Etymology and distribution of 三分.

Sanbu 【三分】^{レベル2
About 10}  The Japanese surnames etymology dictionary.

Toukyou-to , Tochigi-ken , Saitama-ken .

① variant of 関屋 . Together with Tochigi-ken Nasukarasuyama-shi telling that it was also described as "Sekiya". Estimated in the Edo period. Tochigi - ken Nasushiobara - shi Sekiya tells that Mr. Sekiya lived in 12 years since 1302 (Tsuna year). The place name was also written as "Sekiya". Saitama-ken Iruma-shi It was in Edo period in Ji- tree.

② Occupation . Variant of 関屋 . Yamaguchi-ken Houfu-shi Nitta (Large) Tell the wholesale entrance from the store's name of Sekiya.

※ Topography . Mie-ken Tells that Seki's descendant from Seki cho of Kameyama-shi added "Valley". Estimated in the Kamakura period. 関 Seki reference.