Etymology and distribution of 九海.

Kukai 【九海】^{レベル2
About 10}  The Japanese surnames etymology dictionary.

Tochigi-ken , Kanagawa-ken · Chiba-ken . The old pronunciation in estimation is Okabe. Saitama-ken Kodama-gun Misato-machi It was in the Inomata party of the Musashi Nanba party, which used the Inamata as the basis for the Heian period and the Kamakura period. 岡部 Okabe reference.