[1] The Kōhaku 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 Kōhaku bloodlines established (Tomoin, Sensuke, Yagozen, Manzo).

[2] Today, the Tomoin and Yagozen are the two remaining major Kōhaku bloodlines in Japan.

Kōhaku are bred to have the following characteristics:[4] These are Japanese exhibition standards, and fish purchased simply for display in private homes or to be kept as pets, do not necessarily adhere to these standards.

There are a number of words used to describe the markings on a kōhaku:[5] Tamadachi, Michugo (May 1, 1990).