Koi is the ancestor of the common edible carp. It originated from Pis in Central Asia and was introduced to Japan through China and Korea. In Japan, it was improved to be used as an ornamental carp, and is therefore a purely Japanese work of art.
Early koi were called "color koi," "flower koi," "model koi," "variant koi," etc., and they were called "color koi," "flower koi," "model koi," and "variant koi.
In the early days, Koi was called "color", "flower", "model", "variant", etc., but because the words "color", "flower", etc. were considered by the Japanese to be too warm and soft, and were not suitable for the situation during the Second World War, they were renamed as "Koi "
There are many types of koi such as "German red and white", "German tricolor", "Akitsui" and "Kikusui". In fact, German carp are only for food, but a few of them have been improved to be less scaly or scale-less carp, and their original species is black in color. The Japanese mated these German carp with Japanese koi to produce German-bred ornamental carp, so German-bred koi are also the work of the Japanese.
Koi is a noble large ornamental fish, it is its colorful colors, ever-changing patterns, healthy and powerful body shape, lively and calm swimming posture, won the "king of ornamental fish" reputation. In addition, Japan's fish admirers celebrate the beauty of koi as "living jewels in the water" and "national fish". The one who called it "living jewel in the water" was Komei Koshihara, the president of Nagoya Women's University, and the one who called it "national fish" was Yu Miyahide of Kochiya City, who called it at the first all-Japan comprehensive koi tasting held in Tokyo in December, 1968, and the one who called it "national fish" was Yu Miyahide of Kochiya City, who called it "national fish.