Etymology and distribution of 口井.

The Japanese surnames etymology dictionary.
https://play.google.com/store/apps/details?id=info.jigensha.jcedfreeGoogle Play で手に入れよう https://apps.apple.com/us/app/id1471109324
↑オフライン検索できるアプリもどうぞ
在日通名大全

日本初、在日通名の研究書「在日通名大全」発売中!
ネットの電話帳 住宅地図 マッポン!

「口井」さんの名字の分布数。

カンマ区切りで複数の名字を指定できます。

Etymology of 口井

Distribution of 口井
Ranking
1 Kainan-shi(About 100)
2 Wakayama-shi(About 60)
3 Kaisou-gun Kimino-chou(About 20)
3 Oozu-shi(About 20)
5 Kinokawa-shi(About 20)
6 Iwade-shi(About 10)
6 Tanabe-shi(About 10)
6 Shimonoseki-shi(About 10)
6 Matsuyama-shi(About 10)
10 Takaradzuka-shi(Very rare)
10 Kawanishi-shi(Very rare)
10 Akashi-shi(Very rare)
10 Koube-shi Kita-ku(Very rare)
10 Koube-shi Nagata-ku(Very rare)
10 Arida-shi(Very rare)
10 Daitou-shi(Very rare)
10 Oosaka-shi Miyakojima-ku(Very rare)
10 Kishiwada-shi(Very rare)
10 Matsubara-shi(Very rare)
10 Izumisano-shi(Very rare)
10 Sen'nan-shi(Very rare)
10 Toyonaka-shi(Very rare)
10 Sendai-shi Aoba-ku(Very rare)
10 Oogaki-shi(Very rare)
10 Mihara-shi(Very rare)
10 Hatsukaichi-shi(Very rare)
10 Fukuyama-shi(Very rare)
10 Iyo-shi(Very rare)
10 Tama-shi(Very rare)
10 Yokohama-shi Sakae-ku(Very rare)
10 Sanuki-shi(Very rare)
10 Sukumo-shi(Very rare)