Etymology and distribution of 古桑.

Furukuwa 【古桑】^{レベル3
About 70}  The Japanese surnames etymology dictionary.

Shimane-ken Masuda-shi , Yamaguchi-ken . Creation . Tells you from "Yayori" which is the kanji notation of "Noi heavy" of "The snowy heavy fountain falling today in the early spring of the beginning of the new year" by the owner of the Nara era at the end of the "Manyo Shu" . Location unknown. "Wonderful things overlap." 大伴 Ootomo reference.

* In Shimane-ken western part (formerly: Iwami-kuni) there is a transmission with Mr. Futarumi's descendant. 重富 Shigetomi reference.