Etymology and distribution of 久斎.

Kyuusai 【久斎】^{レベル2
About 30}  The Japanese surnames etymology dictionary.

Aichi-ken , Chiba-ken . Sashima is rare. Originated from Ibaraki-ken Bandou-shi (formerly: Sasima County Kojima (Sasima)). Place name with a record in the notation of "猨 島" in the Nara era. Kouchi-ken Aki-gun Kitagawa-mura In Hisaki tell him that Mr. Kojima of the Heike's lost person has come home. Estimated in the Kamakura period. There is a cojima in the lower stake in the same place. 平 Taira reference.