Doitsu-goi, or German carp. Was first imported to Japan in 1904. Kichigoro Akiyama, a teacher at what is now the Tokyo Fisheries College, cross-bred them with Japanese Asagi Sanshoku (Sanshu koi) to produce a new variety. Excellent specimens of Shusui such as we see today apparently began to appear from around 1928.

Hana Shusui

With some hi markings between the lateral and dorsal line symmetrically on the both sides of the body

Hi Shusui

Its body is largely covered by Hi.

Ki Shusui

Yellow Shusui. If there is no blue ground at all and the scales on the back are black, it should be a Ki Matsuba Doitsu.

Pearl Shusui

With ginrin on the scales of the back.