What Is Unagi? A Guide to Japanese Eel

Sweet, savoury, smoky and wonderfully tender, unagi is one of Japan’s most distinctive foods.

While sushi, ramen and tempura may be more familiar to diners in the UK, Japanese eel has been enjoyed in Japan for generations and is often associated with a special or indulgent meal.

But what exactly is unagi? What does it taste like? What is unagi kabayaki, and how is grilled eel traditionally eaten in Japan?

In this guide, we explore the basics of unagi, from its flavour and preparation to popular ways of serving it. We will also take a closer look at Kagoshima, Japan’s leading region for farmed eel production, and discover how carefully produced Japanese unagi can be enjoyed at home.

■ What Is Unagi?

Unagi is the Japanese word for eel and, in Japanese cuisine, usually refers to freshwater eel such as the Japanese eel, Anguilla japonica.

One of the best-known ways to enjoy it in Japan is unagi kabayaki – eel that has been grilled and finished with a sweet and savoury soy-based sauce.

Grilled unagi is commonly served over freshly cooked Japanese rice as unadon, or in a traditional lacquered box as unaju. You may also come across it in sushi restaurants, where cooked unagi is used for nigiri and sushi rolls.

Compared with sushi and ramen, unagi may still be less familiar to many people in the UK. Yet its combination of tender fish, rich umami, caramelised sauce and warm rice makes it one of the most memorable ways to explore Japanese food beyond the familiar classics.

■ What Does Unagi Taste Like?

Unagi has a rich, savoury flavour and a soft, tender texture. When prepared as kabayaki, it also develops a gentle sweetness and a fragrant grilled character.

The flavour is quite different from many white fish. Unagi has a natural richness that gives the flesh a succulent texture and helps it stand up to the bold kabayaki sauce.

As the eel grills, the outside develops a slightly caramelised finish while the flesh stays tender. A traditional sauce based on ingredients such as soy sauce, mirin and sugar adds sweetness, saltiness and umami without needing complicated seasoning.

For anyone in the UK who enjoys the sweet-and-savoury balance of Japanese sauces such as teriyaki, unagi kabayaki can be an approachable way to try eel for the first time.

And perhaps most importantly, grilled eel is particularly good with Japanese rice. The sauce runs into the warm grains underneath, bringing the rice and eel together in every mouthful.

Explore Japanese Rice

■ What Is Unagi Kabayaki?

Unagi kabayaki is a traditional Japanese preparation in which eel is opened, grilled and coated with a sweet and savoury sauce, typically based on soy sauce, mirin and sugar.

Kabayaki is one of the preparations most closely associated with Japanese eel.

During cooking, grilling adds aroma and colour while the sauce creates the glossy appearance that makes Japanese grilled eel so recognisable. The aim is not simply to make the eel taste sweet; a good kabayaki should allow the natural richness and umami of the fish to remain at the centre of the dish.

If you are trying Japanese unagi for the first time, kabayaki is an excellent place to start. Served over freshly cooked rice, it requires very little else to make a satisfying Japanese-style meal.

Explore Unagi Sauce

■ How Is Unagi Eaten in Japan?

There is more than one way to enjoy unagi in Japan. From a simple rice bowl to sushi, each style highlights the flavour of grilled eel slightly differently.

・ Unadon

Unadon is a Japanese rice bowl topped with unagi kabayaki.

It is one of the simplest ways to enjoy Japanese eel. Warm rice is topped with grilled unagi, usually with some kabayaki sauce spooned over the top.

Because the dish is so straightforward, the quality of the rice and eel matters. The warm rice absorbs some of the sauce while balancing the richness of the fish.

For someone discovering unagi at home for the first time, unadon is a great starting point.

・ Unaju

Unaju also combines grilled unagi and rice, but is traditionally served in a rectangular lacquered box known as a jubako.

The fundamental combination is similar to unadon, although unaju is often associated with a more formal or special dining experience in Japan.

It is a wonderfully simple idea: good rice, carefully prepared eel and a flavourful kabayaki sauce.

・ Unagi Sushi

Unagi can also be enjoyed as sushi.

Unlike many familiar types of sushi that use raw seafood, unagi sushi uses cooked eel. Grilled eel can be placed over seasoned sushi rice as unagi nigiri or used inside sushi rolls.

Its sweet-savoury flavour makes it particularly enjoyable with lightly vinegared sushi rice.

■ Unagi vs Anago: What Is the Difference?

Unagi and anago are both used in Japanese cuisine, but they are not the same type of eel.

In Japanese food, unagi generally refers to freshwater eel, including Japanese eel, while anago refers to conger eel, which is a marine species.

They also tend to have different characteristics when served.

Unagi has a richer, fattier flavour and is especially well known in kabayaki, unadon and unaju. Anago is usually lighter and more delicate, and is often found in sushi and tempura dishes.

So if you see both names on a Japanese menu, they should not be treated as interchangeable.

For the rich, glazed Japanese grilled eel commonly served over rice, it is unagi that you are most likely looking for.

■ Why Is Kagoshima Famous for Unagi?

Kagoshima is Japan’s leading prefecture for farmed eel production and is one of the country’s most important regions for Japanese unagi.

According to official data published by the Kagoshima Prefectural Government, Kagoshima accounted for 41% of Japan’s farmed eel production in 2022, ranking first in the country.

Kagoshima, situated in southern Japan, has a major aquaculture industry. The prefecture also ranks highly in the farming of other seafood, including yellowtail and greater amberjack.

Knowing where a food comes from can make discovering Japanese cuisine even more interesting.

Just as the origin of wine, cheese or tea can tell you something about the people and practices behind it, Japanese eel also has a story connected to its producer and place of origin.

For unagi, Kagoshima is a name well worth remembering.

■ How Japanese Unagi Is Carefully Produced

The quality of Japanese unagi is not only about how it is cooked. How the eel is raised, the water used during aquaculture, the grilling process and even the sauce can all form part of the finished product.

One producer with a long-standing focus on eel is Yamada Suisan, which produces eel in Kagoshima.

Its flagship Yamada no Unagi “Iki” is made using eel from Kagoshima and is designed to highlight the natural umami, richness and aroma of the eel itself.

・ Raised in Kagoshima Groundwater

Yamada Premium Japanese Unagi Iki is raised from fry in Shibushi, Kagoshima.

According to the product information, the aquaculture ponds are supplied with groundwater pumped from approximately 80 metres below ground.

・ Raised without Medicinal Treatment

The eel used for Yamada no Unagi Iki is raised without antibiotics or medicinal treatment, with the growing environment carefully managed throughout the process.

・ Slowly Grilled over Charcoal

After being raised in Kagoshima, the eel is grilled over charcoal.

For Yamada Premium Japanese Unagi Iki, the grilling process takes approximately 1.5 times longer than the producer’s standard production line, helping to develop a fragrant exterior while keeping the inside tender and succulent.

・ Finished with a Simple Kabayaki Sauce

Yamada Suisan uses a simple sauce based on soy sauce, mirin and sugar for its Iki unagi, with the aim of allowing the flavour, natural richness and grilled aroma of the eel to stand out.

It is a useful reminder that when choosing Japanese eel, there is more to consider than simply size or price.

Origin, aquaculture, grilling and seasoning all help tell the story of the unagi on your plate.

■ Can You Use Unagi for Sushi?

Yes. Cooked unagi is widely used for Japanese sushi and works particularly well with seasoned sushi rice.

If you are searching for eel for sushi, unagi kabayaki is an excellent option because it is already cooked and seasoned.

Its rich, sweet-savoury flavour contrasts nicely with the gentle acidity of sushi rice.

・ Unagi Nigiri

To make simple unagi nigiri at home, shape seasoned sushi rice into small pieces and top each one with a slice of warmed grilled eel.

A thin strip of nori can be wrapped around the middle if you wish.

・ Unagi Sushi Rolls

Unagi also works well inside sushi rolls.

Cut the grilled eel into strips and combine it with sushi rice, nori and ingredients such as cucumber or avocado.

Because kabayaki already has plenty of flavour, you do not need to add lots of additional seasoning.

It can also make an excellent filling for temaki, or hand-rolled sushi, when sharing a Japanese-style meal with family or friends.

■ How to Enjoy Unagi at Home

Ready-cooked unagi kabayaki makes it surprisingly easy to enjoy Japanese grilled eel at home.

You do not need a specialist Japanese kitchen or complicated preparation. Once the eel is properly defrosted and heated according to its pack instructions, a few simple ingredients are enough.

・ Make an Easy Unagi Don

The easiest option is also one of the best.

Cook a bowl of Japanese rice, warm the grilled eel and place it on top. Add a little extra sauce if desired.

Japanese sansho pepper or finely shredded nori can make excellent finishing touches.

The result is a simple unagi don that allows the eel to remain the main flavour.

・ Make Unagi Sushi

For something a little more hands-on, prepare sushi rice and turn the eel into unagi nigiri, sushi rolls or temaki.

This is also an enjoyable way to introduce someone to Japanese eel if they already like making sushi at home.

・ Create a Japanese-Style Unagi Meal

Serve grilled eel and rice alongside miso soup and Japanese pickles for an easy Japanese-style meal.

The rich flavour of the eel works particularly well with simple side dishes that provide contrast rather than competing with the main dish.

Yamada Premium Japanese Unagi Iki is ready to eat once defrosted, although heating is recommended. The product instructions suggest microwaving it at 600W for around one minute, with the option of lightly grilling the eel afterwards for a more aromatic finish.

Always follow the preparation and storage instructions shown on the product packaging.

■ Frequently Asked Questions About Unagi

■ Discover the World of Japanese Unagi

Japanese food goes far beyond sushi and ramen.

Unagi is a wonderful example of how a seemingly simple combination – grilled fish, sauce and rice – can reflect regional ingredients, specialist production and generations of Japanese food culture.

From understanding what unagi tastes like to discovering the importance of kabayaki and learning why Kagoshima is so closely connected with Japanese eel, there is much more behind this Japanese favourite than first meets the eye.

And the easiest way to understand it may simply be to taste it for yourself.

For anyone in the UK looking to discover authentic Japanese grilled eel, Yamada Premium Japanese Unagi Iki offers the chance to enjoy Kagoshima-produced unagi at home.

View Yamada Premium Japanese Unagi Iki

■ Sources

• Kagoshima Prefectural Government – “Food Industry”

  2022 farmed eel production data: Kagoshima accounted for 41% of Japan’s total production and ranked No. 1 nationally.

  View official Kagoshima Prefectural Government source
• Yamada Suisan Co., Ltd. – Eel Products / Yamada no Unagi Iki

  Information on Kagoshima origin, medication-free aquaculture, kabayaki sauce and product characteristics.

  View Yamada Suisan source
• Yutaka Shop Online – Yamada Premium Japanese Unagi Iki

  Information on production in Shibushi, groundwater, charcoal grilling, ingredients and serving instructions.

  View product information