Utsurimono: Shiro, Hi, and Ki Utsuri, the bicolored black koi carp

Some koi are noticed for their red, while others are noticed for their black. Utsurimono belong to the second category: deep black enveloping the body, broken up by large areas of white, red, or yellow. An Utsuri koi is a black koi with one additional color: white for Shiro Utsuri, red for Hi Utsuri, or yellow for Ki Utsuri. Behind this apparent simplicity lies one of the most difficult families to judge, because its black, sumi, continues to evolve for years. Here is how to read it, distinguish it from its cousins, and buy it without unpleasant surprises.

What does “Utsuri” mean?

The word evokes a reflection, an image reflected back. It is often interpreted as the idea of one color reflecting in another: white in black, black in red. Whatever the exact translation, what matters is understanding how these fish are built. With most koi, we imagine a base color onto which patterns are placed. With Utsurimono, black serves as the base, and the second color appears as “windows” opened in that black.

The family has three main members. Ki Utsuri, black and yellow, is the oldest: its origins date back to the end of the 19th century. Shiro Utsuri and Hi Utsuri became established in the first half of the 20th century, closely linked to the breeding of Showa. Doitsu versions also exist (Doitsu Shiro Utsuri, for example), as do versions with reflective scales (Gin Rin Shiro Utsuri) and metallic versions, Kin Ki Utsuri or Gin Shiro, which competitions classify among the metallic varieties.

The base sumi: how to read it

The black of Utsurimono has a very distinctive structure, also found in Showa. Four markers make it possible to recognize it with certainty.

• It wraps around the body: the black bands start at the back and descend broadly below the lateral line, sometimes all the way to the belly. Seen in profile, the black “clothes” the fish.
• It covers the head: sumi that divides the skull into two or three areas, often in a lightning-bolt or V shape, is highly prized. Japanese enthusiasts call this menware.
• It marks the pectoral fins: a black spot at the base of the pectoral fins (motoguro) is typical and sought after. Entirely black pectoral fins, however, are less appreciated.
• It has depth: beautiful sumi is not simply a spot sitting on the surface; it seems to rise from within the skin, with a texture often compared to lacquer.

Conversely, small, well-rounded black spots on the back, with no black on the head or below the lateral line, identify a Bekko: a white, red, or yellow fish decorated with black spots, rather than a black fish opened up by colored windows. Confusion is common with young fish, when the sumi is still only sketched out.

Utsuri, Showa, Bekko: the differences at a glance

For Hi Utsuri, the reasoning is the same: if you find clear white in addition to black and red, you are probably looking at a Showa. For Ki Utsuri, yellow replaces red, and the “Bekko” equivalent would be a Ki Bekko, yellow with black spots placed on the back, rarely seen in Europe.

The three Utsuri in detail

Shiro Utsuri: black and white

It is the most widespread and, for many enthusiasts, the most graphic. A beautiful Shiro Utsuri presents a balance between black and white, with neither color overpowering the other. The white must be pure, without yellowing or a gray veil, and the boundaries between black and white must be sharp. The sumi on the head is a major criterion: an entirely white head weakens the fish, while a skull divided by a well-defined black lightning bolt enhances its value.

Hi Utsuri: black and red

Hi Utsuri is more delicate. Its red often leans toward orange, and it is common for it to be less dense than that of a Kohaku in the same class. Deep, uniform red from nose to tail, with well-placed sumi, remains rare. Young Hi Utsuri sometimes show areas of black that are still blurred through the red, which may or may not become clearer over time: this is one of the varieties where buying a very young fish is most of a gamble.

Ki Utsuri: black and yellow

Historically the first, it is now the least common. Obtaining a clear, uniform, stable yellow on a fish that also carries deep sumi is difficult. Many Ki Utsuri have pale yellow, or yellow that turns cream with age. When you come across a Ki Utsuri with a rich lemon-yellow color and lacquer-black markings, you are looking at a fish that many collectors search for years to find.

The evolution of black: the heart of the matter

That is the whole difficulty with Utsurimono. The sumi of a young koi is rarely definitive. On a tosai, that is, a first-year fish, it often appears gray, bluish, diffuse, and sometimes is only visible beneath the skin. Over the seasons, it may:

• to become denser: gray becomes black, and the boundary with the white becomes more defined;
• to spread: new black areas appear, sometimes where they were not expected;
• to recede: a black area shrinks or disappears, and the white regains ground;
• to settle: in many fish, the pattern stabilizes at around three to five years of age, but some continue to develop much later.

Biologically, what we see depends on the number of melanophores, their depth in the skin, and the dispersion of pigment within these cells. Melanophores respond to stress hormones, light, and temperature: this explains why a well-established sumi can temporarily fade after transport or in the middle of summer, then return when conditions settle down. This reversible phenomenon has nothing to do with the genetics of the pattern, which determines the final map of the black.

Breeders often speak of sumi as “rising” or “descending.” Without getting into the nuances of terminology, remember this practical rule: a young Utsuri with sumi that is still gray but well placed, especially on the head, has a good chance of becoming a beautiful fish. A young fish that is already very black, with sharply defined boundaries from its first year, may also turn out excellent, but leaves less room for the future: it may become too black.

Water, temperature, and sumi: what really helps

Many things are attributed to water. Here is what consistently comes up in the ponds we monitor, to be presented as trends rather than laws.

Many enthusiasts also find that relatively hard water, with a comfortable KH, seems to encourage deep sumi, whereas very soft, acidic water may make it more fragile. The exact reasons remain debated; what is certain is that poorly buffered water is unstable, and instability is bad for colors as well as health. If your test strips show a low KH, start there.

When it comes to food, the rule varies by variety. For a Hi Utsuri or a Ki Utsuri, food rich in carotenoids helps the red and yellow express themselves. For a Shiro Utsuri, whose value partly lies in the purity of its white, it is better to be more measured: excess pigments can tint the white areas. In a mixed pond, alternating color food with a staple food makes it possible to feed everyone. Our article on the benefits of Saki-Hikari food for koi explains the differences between the product ranges.

Choosing an Utsuri: the buying checklist

1. Look at the head first: presence and shape of the sumi, and the cleanliness of the white (or density of the red and yellow) around it.
2. Check the balance: neither a nearly all-black fish nor a nearly all-white fish. A close-to-balanced ratio is often the most harmonious.
3. Observe the quality of the black: on an adult fish, it should be deep and uniform; on a young fish, grey areas beneath the skin are normal and may be promising.
4. Check the edges: sharp boundaries between black and the secondary color are desirable. Sumi that blends into a gradient is less appreciated.
5. Look at the pectoral fins: well-defined motoguro, symmetrical if possible.
6. Don't forget the fish itself: balanced body, normal swimming, intact fins, no lesions. The most beautiful color cannot compensate for a fish in poor health.

To put a price into perspective, remember that an Utsuri is judged as much on its promise as on its current condition. Our article on estimating the price of a koi carp provides the main guidelines; with Utsurimono, the difference between a pond fish and a show-quality fish depends almost entirely on the quality of the sumi and the purity of the second color.

Common mistakes and practical cases

A common case: “my Shiro Utsuri is turning grey in summer.” In the vast majority of cases, the black returns in autumn. Nevertheless, check that the water quality is not deteriorating in the heat: oxygen, nitrites, and pH at the end of the day. If the water is healthy, let time take its course.

A common case: “the black is taking over the white.” Some bloodlines produce fish that gradually become blacker. This cannot be prevented, but you can anticipate it when buying by choosing a young fish whose white still clearly predominates.

A classic mistake: buying a young Bekko while thinking you are buying an Utsuri. Look at the head and the underside of the lateral line: no black, no Utsuri.

Another mistake: judging a fish that has just been transported. Travel stress temporarily alters the sumi. A fish observed calmly in its pond a few weeks later may look very different. This is also why clear water, thanks to a properly sized UV unit, helps so much when appreciating predominantly black koi: in green water, they literally disappear.

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Frequently asked questions

— What is the difference between a Shiro Utsuri and a Shiro Bekko?

The Shiro Bekko is a white koi with small black spots on its back, without black on the head. The Shiro Utsuri is a black koi with large white areas: its sumi extends below the lateral line and marks the head.

— Why is the black on my Utsuri koi disappearing?

Sumi often recedes temporarily after a temperature change, stress, or pH variation. In young fish, it may also shift before settling. If it does not return after a few months in stable water, it is probably the fish's genetics.

— Is a Hi Utsuri a Showa without white?

This is the simplest way to describe it: black and red, without white. The two families are also closely related, and a Hi Utsuri with a little white is close to a Showa.

— Is Ki Utsuri rare?

Yes, beautiful Ki Utsuri are rare. Yellow is difficult to achieve both pure and stable, and many fish have pale yellow or irregular sumi.

In summary

• Utsurimono = black base + one color: white (Shiro), red (Hi), or yellow (Ki).
• The sumi envelops the body, extends below the lateral line, spreads across the head, and often reaches the base of the pectoral fins.
• Shiro Utsuri: a Showa without red; Hi Utsuri: a Showa without white; Bekko, on the other hand, retains black spots on its back.
• Young sumi is gray and blurry: it becomes denser and shifts over the years.
• Stable water, sufficient KH, and low stress produce deeper, longer-lasting black.

Last updated: October 3, 2026.