Etymology and distribution of 古坪.

Furutsubo 【古坪】^{レベル1
Very rare}  The Japanese surnames etymology dictionary.

Shimane-ken Un'nan-shi · Tottori-ken . A variant of 伊達 . Tottori - ken tells Shimane - ken that he made a mistake in the Meiji New Family Name with Date last name since Warring States Period. Estimated old pronunciation is idi. 伊達 Date reference.