Etymology and distribution of 一岩.

Ichiiwa 【一岩】^{レベル3
About 60}  The Japanese surnames etymology dictionary.

Niigata-ken , Shiga-ken , Kagawa-ken . Niigata-ken Shibata-shi Otemachi was in the Edo period in the Shintokida clan of the clan office. There was a record in Osaka-fu Katano-shi (formerly Kono-gun) in 1321 (Yuan's first year). 犬甘 last name available. 犬甘 Inukai reference.