Etymology and distribution of 沖久保.

Okikubo 【沖久保】^{レベル2
About 10}  The Japanese surnames etymology dictionary.

Oosaka-fu , Mie-ken , Hyougo-ken . Distribution including Toshimi. In Mie - ken , Kagami. Tell him that descendants of Genjima, the warlord of the Heian period, called in the Kamakura period. The old pronunciation in estimation is Toshimi, Rimi. 源 Minamoto reference.