Etymology and distribution of 玄海.

Genkai 【玄海】^{レベル3
About 200}  The Japanese surnames etymology dictionary.

Aichi-ken Nagoya-shi . Korean type . Terrain . Added "river" to Cai. Aichi-ken Nagoya-shi There is a record of naturalization on February 16, 1983 in Minato-ku. The real name is Cai. 蔡 Sai reference.