Eel (Unagi) in Sushi

What is Unagi?

What Kind of Fish is Unagi?

Eels (Unagi) are unique fish that spawn in the sea but mature in rivers. While they are commonly caught in rivers, finding them in the sea is quite rare. Eels caught in the sea are known as "umi-unagi" (sea eels) and are considered a culinary delicacy.

The flavor of unagi varies depending on its habitat. Eels raised in the sea have a cleaner, milder taste, as they lack the muddy aroma and distinctive flavor often associated with river eels. Even among river eels, those caught near river mouths tend to have a softer, more appealing taste.

It's also worth mentioning that unagi (eel) and anago (conger eel) are entirely different species, despite both being enjoyed in Japanese cuisine. In the United States, eating unagi as sushi is relatively common, but in Japan, it is actually quite rare to see unagi served in sushi form.

Best Season for Unagi

The best season for enjoying unagi is from October to December. During this time, eels prepare for hibernation by storing extra fat, making their meat exceptionally tender and flavorful.

Famous Unagi-Producing Regions in Japan

Wild-Caught Eel

Eels sourced from areas with clean water are especially delicious.

1. Shimanto River (Kochi Prefecture)
2. Lake Hamana (Shizuoka Prefecture)
3. Yanagawa (Fukuoka Prefecture)

Farm-Raised Eel

Most of the eel consumed in Japan today is farm-raised.

1. Kagoshima Prefecture: Rich in glass eels (juvenile eels).
2. Shizuoka Prefecture: Recognized as the birthplace of unagi farming.
3. Aichi Prefecture: Known for its pristine water conditions.

While farm-raised unagi might lack the stronger flavor associated with wild unagi, its gentler, milder taste makes it generally easier to enjoy.

When Do Japanese People Eat Unagi?

In Japan, unagi is considered a luxury food, enjoyed as a treat on special occasions. However, there's a unique cultural practice of eating unagi on a specific summer day known as "Doyo no Ushi no Hi" (Day of the Ox). It is believed that unagi’s rich nutrition provides people with the strength to withstand the intense summer heat.

Ways of Preparing Unagi in Japan

Unagi Sushi

Unagi sushi is quite common in the United States, but not as prevalent in Japan. Instead of unagi (eel), the Japanese typically use anago (conger eel), which is gently simmered in a sweet and savory sauce before being served as sushi.

Traditional Edo-style sushi, originating from Tokyo, rarely uses river-caught eel. This is because Edo-style sushi uses ingredients sourced from Tokyo Bay. On the other hand, Kansai-style sushi, commonly found in the Kansai region, occasionally features eel as a topping. Additionally, many conveyor belt sushi (kaiten-zushi) restaurants throughout Japan serve unagi sushi.

Kabayaki (Grilled Unagi)

Kabayaki is the most popular way to enjoy unagi in Japan. The cooking style varies distinctly by region. In Kansai, the eel is split open from the belly, then repeatedly coated with sauce and grilled to achieve a crispy texture. In Kanto, the eel is split open from the back, grilled once, then steamed, and finally grilled again with sauce, resulting in a soft, tender texture.

The reason behind the Kanto method of splitting from the back is rooted in tradition. Historically, cutting from the belly was reminiscent of seppuku (ritual suicide), so it is considered inappropriate in Kanto, where samurai culture was prominent.

Unaju (Grilled Unagi Rice Box)

Unaju is a traditional Japanese dish consisting of grilled unagi (kabayaki) served atop a bed of rice in a rectangular lacquered box (jubako). Although unagi sushi is uncommon in Japan, unaju is widely recognized as the classic Japanese eel dish.

Unaju dishes are often categorized by quality levels using a special ranking system: Matsu (pine), Take (bamboo), and Ume (plum), with Matsu representing the highest grade. This ranking system is used exclusively in Japan to signify the degree of luxury and richness of the unagi meal.

Shirayaki (Plain Grilled Unagi)

Shirayaki is unagi grilled without any seasoning, allowing the natural, delicate flavor of the fish to shine. It is typically enjoyed with a pinch of salt or a touch of wasabi to subtly enhance its taste.

Hitsumabushi (Chopped Grilled Unagi Rice)

Hitsumabushi is a regional specialty from Nagoya, consisting of finely chopped grilled unagi served atop rice in a round wooden container called (ohitsu). Unlike unaju, hitsumabushi can be enjoyed in various ways. You can savor it as is, add condiments such as green onions and wasabi, or pour dashi broth over it to create a flavorful soup-like dish. This versatility makes hitsumabushi especially popular among both locals and visitors.

Recommended Unagi Sushi Restaurants in the Osaka-Kyoto Area

Sushidokoro Kaihara (寿司処 かい原) / Osaka

Bib Gourmand

Michelin Guide, 2025

Sushidokoro Kaihara, recognized as a Bib Gourmand for eight consecutive years, offers exceptional quality at great value. Guests can enjoy a creative omakase course featuring an elegant combination of sushi and side dishes, all for under 10,000 yen. Unagi is occasionally served as a nigiri piece. With its calm, intimate counter seating, the restaurant provides a relaxing atmosphere that pairs perfectly with sake or wine. It's also highly popular among international visitors.

Sushi Rakumi (鮨 楽味) / kyoto

One Star

Michelin Guide, 2025

At Sushi Rakumi in Kyoto, unagi is served as shirayaki (plain grilled), allowing diners to fully appreciate the fish's delicate, natural flavors.

Recommended Unaju Restaurants in Tokyo

Ishibashi (石ばし) / Unagi

Selected Restaurant

Michelin Guide, 2025

Ishibashi, established in 1910, is a renowned unagi restaurant awarded one Michelin star. The restaurant specializes in high-quality unagi sourced from Shizuoka and Kyushu, carefully prepared by third- and fourth-generation chefs from the founding family. The signature unaju features a delicately flavored sauce and premium Niigata rice, creating a perfectly balanced dish.

Nodaya Iriya-Kishimojin Tokyo (入谷鬼子母神門前のだや) / Unagi

This traditional unagi specialty restaurant, founded in 1868, is known for its beautifully grilled, golden-brown eel, prepared using a unique kabayaki method. The eel is domestically sourced and natural, ensuring consistently high quality. Diners can choose between Kanto-style and Kansai-style sauces while watching the live grilling process firsthand, making for an authentic dining experience.

Ginza Yondaime Takahashiya (銀座 四代目 高橋屋) / Unagi

Selected Restaurant

Michelin Guide, 2025

This historic restaurant, established in 1873, is located in Ginza and featured in the Michelin Guide. Ginza Yondaime Takahashiya specializes in Kanto-style eel, which is steamed and grilled to perfection. The signature eel bowl, characterized by its light, flavorful sauce and delicate texture, is worth indulging in.