Goshiki Koi: How to Judge the Koi That Changes with the Seasons

Goshiki means five colours, and the name is older than the fish it now describes. What you are looking at is a Kohaku pattern laid over an Asagi base: red on top, and underneath it a white or blue-grey ground with every scale edged in dark. It inherits the best thing about each parent variety, a Kohaku's red and an Asagi's netting, along with the one thing that makes it a different purchase from either: it changes.

Most of what follows comes from Kazuhiro Hirasawa, who breeds Goshiki at Kanno Koi Farm in Niigata, a farm known above all for this variety. He went through three of his prize-winning Goshiki with Zak in episode 2 of What Makes Koi Beautiful?; the full episode is written up in What Makes a Koi Beautiful? Kanno's Goshiki.

Light and dark Goshiki

The base of a Goshiki is reticulated, each scale outlined so the body reads as a net, and the ground inside the net runs from near-white to dark blue-black. Modern Goshiki are usually spoken of in two types:

• Light Goshiki, with a pale base and fine netting, so the fish reads like a Kohaku with a delicate mesh over the white.
• Dark Goshiki, often called Kuro Goshiki (kuro is Japanese for black), with a deep blue-black base that makes the red stand off it like lacquer on slate.

Zak's customers mostly want the dark kind. "People really like the Kuro Goshiki," he said at Ozumi Ikarashi. Goshiki also come Ginrin (Gin Goshiki), Doitsu and Tancho, and a Goshiki with Showa-style sumi added is a Goshiki Showa.

Why some areas go white and others black is a question Zak put to Hirasawa directly. His answer: "That's because it's Goshiki. If it were all black, it would be Hi Utsuri." The mix is the variety.

The same fish, black one season and blue the next

The thing to know before you buy a Goshiki is that its base colour is not fixed. Hirasawa showed Zak one of his champions twice: at the Nagaoka Koi Show in 2025, and six months later. In the second photo it is far blacker. Asked for the technique, he said there wasn't one. "The water. And the temperature of the water." Cold winter water in the greenhouse brought the black up. And it doesn't stay: "It changes again. It goes back to blue, then turns black again." His summary of the variety: "Goshiki are difficult."

Water matters as well as temperature. Harder water is better, Hirasawa said, and water in Japan varies from farm to farm. In Miami, Zak has seen both outcomes: a Goshiki can hold its dark look here, and one can also turn white later. "In Miami, Goshiki change a lot, and you want it to stay black." That is why the farm and the bloodline matter so much with this variety.

What to look for

Body first, as always. Hirasawa's first reason for picking his champion was "a full body," before the pattern.

The red. A Goshiki's beni is judged like a Kohaku's: deep, even, no thin patches. Hirasawa told us on our winter visit that the beni is the best thing about his fish and the hardest thing to get. The best of it is what Zak calls floating beni, red that looks as though it sits on top of the fish, with no black showing through it at all. "That's really difficult. Really, really difficult."

The edges are more forgiving than on a Kohaku. On a Goshiki, Hirasawa explained, even where there is some sashi at the front edge of a red patch, "the sumi covers it, so you can't see it." What you can see should still be clean, and the white ground, where there is white, should be pure.

Pattern and balance. His Champion B Goshiki has a maruten pattern, a separate red mark on the head as well as the body pattern, and what he liked was the balance between them. Kanno's patterns, as Zak puts it, "are always interesting."

The reticulation. Every scale on the base should be outlined, evenly, over the whole body. Patchy netting, or netting that fades toward the tail, is a fault. Mr. Ikarashi's best Goshiki this year was neither light nor dark exactly, and Zak described what he liked about it: "It has depth to it. The beauty has depth. Every single scale, you see the sumi."

Blue isn't a fault

Buyers who want a dark Goshiki can write off a blue one too quickly. One of Hirasawa's Goshiki never goes as dark as the others and took Grand Champion B at the Junior Koi Show anyway: "Above all, it's beautiful." Another, a little blue at the moment, won Young Champion at the All Japan Young Koi Show against Showa, Kohaku and Sanke. "It's beautiful even when blue." Its red runs all the way to the tail, which some people mark down; Hirasawa doesn't.

Bloodline, and why the male matters

Clean red on a Goshiki is bred, not lucky. Asked how Kanno gets red with no black coming through, Hirasawa's answer was the male: "I used a clean male." The female needs size and decent quality; "the male is the most important."

The farms whose Goshiki hold their darkness for us are Kanno and Ozumi Ikarashi, both in Niigata, and both for the same reason. Mr. Ikarashi told us his Goshiki line is a cross he has worked on over many years, mixing in Kanno and Kawakami blood among others. It is a line he keeps adjusting.

Buying a Goshiki young

Because a Goshiki moves with the seasons and keeps developing as it grows, a young one is a bet on what it will become. The rule Zak applies to Kujaku applies here: buy the frame, the red, and the sign of depth coming, not the fish that looks best in the tank today. At Kanno, Zak chose from the higher-quality batch of Goshiki and Gin Goshiki in the greenhouse, fish he had helped sort as fry the summer before. "It's so much fun to see the beni develop." The honest warning is the same as for any variety that changes: some will go lighter than you hoped. The age trade-off is in tosai, nisai or sansai.

Keeping one

Expect the change and enjoy it; a Goshiki that goes darker in cool water and bluer in warm water is doing what Goshiki do. Stable water keeps the white parts clean. If a dark Goshiki goes pale and stays pale, that is usually the bloodline, which is why the farm it came from is worth knowing before you buy.

Hirasawa's last word in the episode applies to Goshiki more than most: "Koi are not just a pattern. The koi you like and choose is the best koi."

Our Goshiki come mostly from Kanno and Ozumi Ikarashi, and both farms have their own posts: Kanno Koi Farm and Ozumi Ikarashi Koi Farm.

Browse our Goshiki, or every koi we currently have available, each listed with video of the exact fish. Live koi ship Tuesdays and Wednesdays, anywhere in the USA.