Etymology and distribution of 延坂.

Nobusaka 【延坂】^{レベル2
About 20}  The Japanese surnames etymology dictionary.

Hiroshima-ken Onomichi-shi . Hiroshima-ken Onomichi-shi Itoshi Tonomachi is home based. The owner of Oyama shrine in the same place tells that Mr. Fujiwara returned home and called it. Estimated in the Kamakura period. 藤原 Fujiwara reference.