Etymology and distribution of 改口.

Kaiguchi 【改口】^{レベル2
About 10}  The Japanese surnames etymology dictionary.

Shiga-ken , Toukyou-to , Kyouto-fu . Terrain . From the gate and the slope. Shiga-ken Kouka-shi Mizuguchi Town Honmaru was in the Edo era as a clan of the mouth of the clan government office. Iwate-ken Miyako-shi In Kariya, tell Kida surname was Shimane-ken Eastern (formerly Izumo nation) from Kuroda surname. 黒田 Kuroda reference.