Etymology and distribution of 井之口.

Inokuchi 【井之口】^{レベル4
About 800}  The Japanese surnames etymology dictionary.

Fukuoka-ken , Kagoshima-ken , Ooita-ken .

① Ooita-ken originated from Iwa-ya in Kusu-gun. Period, location unknown. Ooita-ken Taketa-shi (formerly Naoyasi ) was in the Muromachi period. Ooita-Ken Ooita-Shi near Haneda (formerly: Iwaya) of the Kamakura period, Ooita-Ken Kitsuki-Shi Iwatani (Iwaya (formerly: Iwaya)) is the Muromachi period, Ooita-Ken Kunisaki-Shi Kunisaki-cho Iwaya, Ooita-Ken Usuki - shi Nozu Town Daiki Iwa-ya is a place name with a record since the Edo period.

② Kagoshima-ken Kimotsuki-gun Kimotsuki-chou Birth of Genda Iwaya. There was Iwadaya in the same place in the Edo period as a gate division system.

③ Kagoshima-ken Minamikyuushuu-shi Originated from Iwaoyonoso, Shimizu's small character, in Kawabe-cho. There was Iwadaya in the same place in the Edo period as a gate division system.

④ variant of 岩谷 . Iwate-ken Morioka-shi Uchimaru was in the Edo period in the clan san Morioka of the clan government. Tradition of the same samurai. 岩谷 Iwatani reference.

Inoguchi 【井之口】^{レベル4
About 800}  The Japanese surnames etymology dictionary.

Toyama-ken Nanto-shi . Toyama-ken Nanto-shi Birth of Iwase. The name of the place called "Iwasanbimura" in the Edo period. Toyama-ken Nanto-shi Distributed in Yamami.