Etymology and distribution of 火.

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

Wakayama-ken . Wakayama-ken Tanabe-shi Originated from the lead of the Ayukawa's small character. Lead mountain "lead" is used. It is said that it was at the entrance of the Lead Mountain mine at Oosaka-fu . Dokuchi at Hokkaidou . In Saitama-ken telling that it was described as "copper mouth". Estimated in the Edo period. The pronunciation is Douguchi. 銅口 Douguchi reference.