The day that people eat eels!      

土用の丑の日(Doyou no ushi no hi=the day of the ox in the term called doyou)

July 25th and August 6th, 2017 are days called “Doyou no ushi no hi” in Japan. If you asked Japanese people “What is Doyou no ushi no hi?”, most of them would answer that “It’s a day that we eat unagi(=eel in English)!” Or, “I’d like to eat unagi, but I don’t since it is kind of expensive.” Why do Japanese eat eels on this specific day in summer? Before I answer the question, let me tell you about the word, “Doyou” and “ushi no hi” first.


The sound is the same as 土曜doyou which means Saturday in Japanese, but this Doyou土用 is different one. There are four terms called Doyou in a year, and they are eighteen or nineteen days before the beginning of each season in the traditional Japanese calendar. In 2017, they are 1/17 ~ 2/3, 4/17 ~ 5/4, 7/20 ~ 8/6, and 10/20 ~ 11/6.

丑の日Ushi no hi

牛 Ushi means ox, cow, or bull in Japanese, but this kanji 丑 Ushi means the ox in the Chinese zodiac, and it had been used for indicating year, month, date, time, or direction instead of numbers or the directions in Japanese. 日(Hi) means “day”, and の(no) means “of”, so “ushi no hi” literally means the day of the ox.

Doyou no ushi no hi is the day of the ox in Doyou term (in summer), and it is July 25th and August 6th in 2017. (The date is not fixed and it changes every year. July 20th and August 1st in 2018, July 27th in 2019, July 21st and August 2nd in 2020)

Apparently. there are some theories about the reason Japanese people started eating eels on Doyou no ushi no hi.

Theory A: Japanese people have eaten eels since the 7th century, and it was believed that if people eat eels, they can get over summer-heat fatigue. Eels contains vitamin A, vitamin B1, vitamin B2, vitamin B6, vitamin B12, vitamin E, DHA, EPA, potassium, calcium, niacin, zinc, folic acid etc. It is interesting that ancient Japanese people regarded eels as nutrient-rich food even though they didn’t know those nutrients at that time.

Unfortunately, there’s no medical proof that eating eels helps people to prevent having summer-heat fatigue any longer since people always eat food with high calories and nutrients in our time, so don’t tend to suffer from fatigue.

Theory B: In Edo period (from 1603 to 1868), Eel-dish restaurants wanted to sell their eels in summer, and they advertised like “It’s ‘doyou no ushi no hi’ today! (So let’s eat eels!)”. (The best season of eels is not summer, but winter since they have more fat in a cold season. It was well-known that eels in summer are not as tasty as in winter, so most people didn’t have a habit to eat eels in summer in Edo period.) People believed that if they ate food starting with the U sound on the day of the ox, they would never suffere from summer heat, and it became common to eat eels on the day of the ox in summer’s Doyou.

There are not many types of dish used eels, and the most common dish is kabayaki, eels grilled with the sauce called “たれ(tare)”. (Tare sauce is normally made from soy sauce, sake for cooking, sugar, etc.)

うな重(Una-jyu) : Grilled eel served over rice in a lacquered box. Eel is ‘unagi’ in Japanese, and jyu is short for jyu-bako, which means a lacquered box.

There’s a similar dish called Una-don, and ‘don’ is short for donburi, and donburi means a bowl in Japanese. In general, una-don is less expensive than una-jyu. It depends on the restaurant, but it is said the difference is the size of the eel. Eel in una-jyu is usually bigger than that in una-don. (I don’t recommend you trying una-don at gyu-don chain restaurants if you want to have good quality of eel dishes.)

Some restaurants have several types of una-jyu, that are ranked in order of quality and portion size such as 松(matsu/shou = pine tree), 竹(take/chiku = bamboo), 梅(ume/bai = plum tree), instead of 特上(toku-jou = the heighest), 上(jou = high), 並 (nami = normal). The price is Mastu= toku-jou> Take= jou > Ume= nami. You might think matsu, the most expensive one has the best quality of all, but their differences are basically just the size of eel. If you want to eat more eels, you can order matsu.

ひつまぶし(Hitsumabushi) : Another dish of eels, invented in Nagoya, Aichi prefecture in Japan. Japanese people tend to divide the dish into quarters and eat at a time in a smaller bowl. Personally, I prefer hitsumabushi to Una-jyu, since I can try different flavors in one dish.

How to eat “Histumabushi”

Firstly, you eat a quarter of hitsumabushi as it is (without adding anything).

To the second quarter, you add some 薬味(yakumi), chopped green onion, shredded seaweed, or white sesame. Yakumi is different depending on restaurants, and my favorite restaurant serves shredded shiso, one of Japanese herbs instead of chopped green onion.

To the third quarters, add your favorite yakumi with wasabi and pour dashi(broth) and eat hitsumabushi like お茶漬け(ocha-zuke= porridge) Finally, you eat the last quarter however you like.

肝吸い(Kimosui) : Kimo means liver in Japanese, and sui usually called 吸い物(suimono) which means clear broth soup. Most of restaurants that fillet eels at their place serve this dish. Although its name means “liver”, they don’t use liver of eels for Kimosui. They use organs stomach.

山椒 Sansho spice : It is Zanthoxylum piperitum in English, and it is called sansho in Japanese. I’m not a big fan of sansho spice, but it is common to eat una-jyu or hitsumabushi (the first quarter) with grinded sansho spice.

There are two big differences in how to cook eels between East and West Japan.

The first difference: East Japan uses ‘sebiraki’ and West Japan uses ‘harabiraki’. “Sebiraki” means cutting open the back of a fish, and “harabiraki” means cutting open the belly of a fish. According to one theory in Osaka, the city of merchants, the belly was split open because it could be cut easier and faster. On the other hand, in Edo (The old name for Tokyo), the city of samurai, slashing the belly(harakiri) was considered a taboo, so sebiraki was common. *Osaka and Edo(Tokyo) have been big cities since Edo period, and if people say West or East Japan, they usually mean the regions around Osaka or Tokyo.

The second difference: East Japan uses steamed and grilled eel, but in West Japan: just grilled. In the Kanto region (east Japan), eel is broiled after it is cut open along the back and steamed. On the other hand, eel is slit open along the belly and grilled without steaming in Kansai region (West Japan). I have been to Kansai several times, but I have never tried eels there so I cannot compare which one is better at this moment. (I would be able to find the difference of cooking, but I don’t think I would find which way the eel was cut, sebiraki or harabiraki.)

I will definitely try una-jyu when I go to Kansai next time, and update this article!


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