Etymology and distribution of 古屋瀬.

Koyase 【古屋瀬】^{レベル1
Very rare}  The Japanese surnames etymology dictionary.

Kyouto-fu , Kouchi-ken . It was recorded in Yoshimizu Castle located in Kyoto Okayakura Town, Yamashina-ku, Kyoto City, and it was recorded in 1558 (Yuanroku first year). The castle tells that Mr. Shima Toshi built a castle.