Etymology and distribution of 相井.

Soui 【相井】^{レベル3
About 300}  The Japanese surnames etymology dictionary.

Ishikawa-ken Nanao-shi · Toyama-ken Takaoka-shi . 出口 Surname is included.

Aii 【相井】^{レベル3
About 300}  The Japanese surnames etymology dictionary.

Fukuoka-ken , Niigata-ken , Saga-ken .

① Nagasaki-ken Sasebo-shi A origin of the Ainoura town. Place name with a record since the North / South morning era. Mr. Watanabe visited in 1145 (Hisan first year) and tells that Saga-ken Taku-shi Hokuu Taku-shi Hokuhaku Town Hakuba Ao no Ura moved to 1179 (3 years old). The old pronunciation Ainuaura of the surname is rare. 渡辺 Watanabe reference.

② Originated from Toyama-ken Himi-shi near the 12th town (old: Aiura). A place name with a record since the Heian period.