Big round eyes.

A flowing tail.

And a face that's almost impossible to forget. 👀🐟

This is the Demekin (出目金)—one of Japan's most recognizable varieties of fancy goldfish.

Its most famous feature is right there in its name:

those enormous, protruding eyes.

Often seen at Japanese summer festivals, goldfish exhibitions, and ornamental ponds and aquariums, Demekin have become part of the colorful world of Japanese goldfish culture.

But where did these unusual fish come from?

And why are their eyes so big?

What Is a Demekin?

Demekin (出目金) is the Japanese name for a type of fancy goldfish distinguished by its large, outward-projecting eyes.

The name can be broken down into:

De (出) — protruding or sticking out
Me (目) — eye
Kin (金) — gold, from kingyo (金魚), meaning goldfish

So Demekin essentially describes a protruding-eyed goldfish.

In English, similar fish are commonly known as telescope goldfish or telescope-eye goldfish.

And once you've seen one, it's easy to understand the name.

Why Are Demekin's Eyes So Big?

A baby Demekin doesn't begin life with enormous telescope-like eyes.

Young fish initially have relatively normal-looking eyes.

As they grow, their eyes gradually begin to protrude outward, eventually creating the distinctive appearance associated with the variety.

This unusual feature is the result of selective breeding.

Over generations, goldfish breeders selected fish with particular physical characteristics, eventually producing the dramatic telescope eyes we recognize today.

The result is one of the most unusual silhouettes in the goldfish world.

Did Demekin Originate in Japan?

Despite being strongly associated with Japanese goldfish culture today, the Demekin's story begins outside Japan.

Fancy goldfish were developed in China through centuries of selective breeding from domesticated forms of the Prussian carp.

Telescope-eyed goldfish are generally believed to have been developed in China before later reaching Japan.

In Japan, the variety became known as Demekin.

Like many aspects of Japanese culture, something introduced from abroad eventually developed its own distinctive place within Japanese life.

The Famous Black Demekin

When many Japanese people hear “Demekin,” one particular fish may immediately come to mind:

Kuro Demekin (黒出目金).

Kuro means black.

The Kuro Demekin has a deep black or dark charcoal body, large protruding eyes, and elegant flowing fins.

Its dramatic appearance makes it very different from the bright orange goldfish most people picture when they hear the word kingyo.

There are also red and multicolored varieties.

But the black Demekin is especially iconic.

Against the water, its round black body and enormous eyes give it an almost cartoon-like personality.

Demekin and Japanese Summer Festivals

Goldfish and Japanese summer are closely connected.

During traditional matsuri (祭り), festival stalls may feature a game called:

Kingyo-sukui (金魚すくい)

or goldfish scooping.

Players use a delicate paper scoop called a poi to try to catch goldfish from a shallow pool without tearing the paper.

Bright orange goldfish swim quickly beneath the surface...

and occasionally you may spot a darker, rounder fish with enormous eyes among them.

A Demekin.

Because of their unusual appearance, they're especially exciting to discover.

What Is Kingyo-Sukui?

Kingyo-sukui looks simple.

It isn't.

You receive a small plastic frame covered with thin paper.

Then you carefully slide it beneath a goldfish.

Move too quickly...

rip.

Leave it underwater too long...

rip.

And the goldfish swims away.

The challenge is to use the water itself to help guide the fish onto the scoop while putting as little pressure as possible on the fragile paper.

Kingyo-sukui has become one of the classic images of a Japanese summer festival alongside fireworks, yukata, shaved ice, and festival food.

And Demekin fit perfectly into this nostalgic summer world.

Goldfish Have a Long History in Japan

Goldfish are not native to Japan.

They were originally domesticated in China and later introduced to Japan.

For a long time, ornamental goldfish were expensive and associated with wealthy households.

As breeding expanded during the Edo period (1603–1868), goldfish gradually became more widely available.

Eventually, keeping and appreciating goldfish became a popular pastime among ordinary townspeople as well.

Different varieties were bred for unusual colors, body shapes, tails, and eyes.

Goldfish weren't simply pets.

They became something to observe and appreciate aesthetically.

Japan's Fascination With Fancy Goldfish

Once you start exploring Japanese goldfish, Demekin is only the beginning.

Japan has developed and embraced numerous distinctive varieties.

There's Ryukin (琉金) with its high back and deep body.

Ranchu (らんちゅう) is famous for its rounded shape and lack of a dorsal fin.

Wakin (和金) has a simpler, more traditional goldfish body.

And then there's Demekin with those unmistakable eyes.

Each variety has particular characteristics that enthusiasts look for.

Body proportions.

Fin shape.

Color.

Swimming style.

Even the way the fish looks from above can matter.

Goldfish appreciation can become surprisingly sophisticated.

Demekin Are Not Just Black

The black Demekin may be the most recognizable version in Japan, but telescope-eyed goldfish can appear in several colors and patterns.

You may encounter:

• Black Demekin
• Red Demekin
• Red-and-white varieties
• Calico varieties
• Other multicolored telescope goldfish

Their colors can also change as they mature.

Goldfish coloration is influenced by genetics, age, environment, and other factors.

So a young fish may not necessarily look exactly the same throughout its life.

Fun Facts About Demekin

• Demekin (出目金) literally refers to a protruding-eyed goldfish.
• In English, similar varieties are commonly called telescope goldfish.
• Their eyes become more pronounced as they grow.
• Telescope-eyed goldfish were originally developed in China.
• Demekin later became established within Japanese goldfish culture.
• Kuro Demekin (黒出目金) is the famous black variety.
• Demekin may appear at Japanese kingyo-sukui festival stalls.
• Their large eyes can make their vision poorer than that of ordinary goldfish.
• Their protruding eyes are more vulnerable to injury.
• Goldfish are strongly associated with summer imagery in Japan.

Frequently Asked Questions

What is Demekin?

Demekin (出目金) is the Japanese name for a fancy goldfish characterized by large eyes that protrude outward from the sides of its head.

What does Demekin mean?

The name comes from Japanese characters associated with protruding (出), eye (目), and gold (金). It essentially describes the fish's most recognizable characteristic—its protruding eyes.

Is Demekin a Japanese goldfish?

Demekin is deeply established in Japanese goldfish culture, but telescope-eyed goldfish are believed to have originally been developed in China before being introduced to Japan.

Why does Demekin have big eyes?

Its unusual eyes are the result of generations of selective breeding. The eyes become increasingly prominent as the fish develops.

What is a black Demekin?

Kuro Demekin (黒出目金) is a black variety of Demekin. Its dark body, flowing fins, and large protruding eyes make it one of the most distinctive Japanese fancy goldfish.

Are Demekin blind?

No, but their unusual eye structure generally means their vision isn't as strong as that of ordinary goldfish. They can also be more vulnerable to eye injuries.

What is kingyo-sukui?

Kingyo-sukui (金魚すくい) is a traditional Japanese festival game in which players try to scoop goldfish from a shallow pool using a fragile paper scoop.

🇯🇵 Keep Discovering Japan

If you enjoyed learning about Demekin, you might also like discovering What Is Ochūgen (お中元)? Japan's Summer Gift-Giving Tradition

👋 Meet a JapPop Resident

Curious Demekin

ギョロデメ

No mystery is too small for Curious Demekin. 🔍🐟

With enormous eyes and a magnifying glass always ready, he investigates anything that looks even slightly suspicious.

Curious, determined, and perhaps a little too observant, he usually makes an important discovery...

there wasn't a mystery after all.

👉 Meet Curious Demekin and discover more residents from the JapPop Universe.

🇯🇵 About JapPop

At JapPop, we celebrate Japanese culture through playful illustrations, original characters, and stories inspired by everyday life in Japan.

From beloved foods and traditional festivals to folklore, historical figures, lucky gods, and language, every article introduces another piece of Japan—and another story worth discovering.

Whether it's a centuries-old tradition or a funny little goldfish with enormous eyes, there's always something unexpected to discover.

Discover Japan, one story at a time. 🇯🇵✨