Etymology and distribution of 岩國屋.

Iwakuniya 【岩國屋】^{レベル1
Very rare}  The Japanese surnames etymology dictionary.

Iwate-ken Toono-shi . A variant of 臼舘 . Iwate - ken Toono - shi In Aosasamachi - Sasa, tell the fact that officials mistyped Usurator 's surname after the office became a fire in the Tokyo era. 臼舘 Usudate reference.