Kitakura 【北倉】4 The Japanese surnames etymology dictionary.
① Convention . Abbreviation for Kumagai. The first element is from "Bear" of Kumagai. In Okayama-ken Okayama-shi tell Kumagai's descendant. 熊谷 reference. Ibaraki-ken Takahagi -shi Takahagi told me that Tochigi-ken is a pioneer.
② Birth of Wakayama-ken southern part · Mie-ken south part (aka: Kumano). A place name with a record since the Nara period. In Wakayama-ken tells me that it came from Kumano. Estimated from tradition is a warring country era.