The Japanese surnames etymology dictionary.
Niigata-ken Itoigawa-shi , Toyama-ken , Ibaraki-ken . Terrain . From under the land. Niigata-ken Jouetsu-shi Shimogoshi of the Sanwa-ku Koshigayo's underwear is a place name unknown in the record era. Nagano-ken Nagano-shi Yoshida (formerly Shimogoshi) is a geographical name with a record since the Sengoku period.