Shusui

Doitsu (scaleless) Asagi. Variety created from the breeding of Doitsu black Koi with Asagi. Kichigori Akiyama in Tokyo first succeeded breeding the Doitsu version of Asagi in 1910. Because this achievement added a Doitsu version to this variety soon other Koi varieties also became more diverse with fantastic new possibilities.

(Courtesy of the excellent Book Kokugyo Vol II)