Kohaku (?? (k?haku "red and white"?)) is a variety of ornamental koi (carp). The Kohaku has a white (shiro) body, with red (aka) markings, or 'hi', across the body. The Kohaku is one of the gosanke; the ‘Big Three’, consisting of Kohaku, Sanke, and Showa.[1]
The Kohaku breed is believed to be one of the first ornamental carp varieties developed. The variety dates to 1888, when a man named Kunizo Hiroi bred a red-headed female koi with one of his own males, whose markings resembled cherry blossoms, thus creating the now extinct Gosuke bloodline from which all of the known Kohaku bloodlines established (Tomoin, Sensuke, Yagozen, Manzo).[2] Today, the Tomoin and Yagozen are the two remaining major Kohaku bloodlines in Japan.[3] The Kohaku remains one of the most popular breeds in Japan. The bright red markings are known as hi (??).
Source From http://en.wikipedia.org/wiki/K%C5%8Dhaku_(fish)