People in Japan have a culture of sensing and enjoying the changing seasons and nature through food. In Japan, there are foods that are prepared in accordance with seasonal events and eating them at these times can be considered auspicious. For example, Nanakusa-gayu (seven-herb rice porridge) is eaten on January 7th at the beginning of the year and is believed to ensure good health. Or Kashiwa mochi (oak leaf-wrapped rice cake) is eaten on the Vernal Equinox Day and is believed to ensure a year of good health and safety.

These auspicious foods, aligned with Japan’s sense of seasons and customs, transform meals for the Japanese from mere acts of nutrition or enjoyment of delicious food into experiences with deeper cultural and spiritual significance.

Doyō no Ushi no Hi is widely known as the day to eat foods which starts with the sound “u” in them, in particular eel in Japan. This article will explore the auspicious food tradition aligned with the day of the Ox in the summer Doyō period called “Doyō no Ushi no Hi“.

Traditions Aligned with the Natural Cycles in Japan

People in Japan nowdays rarely use the terms Doyō or Ushi no Hi (The day of the Ox) in daily life except in the context of particular traditions, because many traditional events in Japan were originally celebrated according to the old calendar known as Kyureki. Despite the fact that Kyureki was replaced by the current Gregorian calendar (solar calendar) in 1873, as the Meiji government implemented modernising measures to align Japan with the West, many seasonal traditions are still celebrated based on Kyureki.

The traditional Japanese calendar, Kyureki, marks the passing of the seasons and changes in the natural world. The Kyureki divides the year into 24 segments known as Nijūshi Sekki, each named to represent a specific season. Each segment is named, such as Risshun (Beginning of spring) in approximately early February and Daikan (Greater cold) in late January.

For example the six segments of the Nijūshi Sekki representing summer are:

The period of each term varies from year to year. Taisho known as “Greater Heat” in English in 2024 is from 22 July to 7 August, which overlaps with the summer Doyō period.

What does Doyō and Ushi no Hi mean?

Doyō no Ushi no Hi means the “Ox Day” during the Doyo period. The Doyō (土用) period is based on the “Yin-Yang and Five Elements Theory” that was introduced from China. In the Yin-Yang and Five Elements Theory, it is believed that the natural world is composed of five elements: wood(木), fire(火), earth(土), metal(金), and water(水). The seasons are also matched to these five elements, with spring corresponding to wood, summer to fire, autumn to metal, and winter to water. The element of earth (土do) was assigned to the 18-day periods before the beginning of each season: Risshun (立春 the start of spring), Rikka (立夏 the start of summer), Risshu (立秋 the start of autumn), and Rittō (立冬 the start of winter). This time was considered when the energy of earth was at its peak, and it was referred to as “Dōyōji (土旺用事)” which eventually became known as “Doyō. In reality, the transition between seasons involves repeating cycles of warming up and cooling down several times before the season fully changes.

On the other hand, Ushi no Hi refers to the day that corresponds to the Ox when counting the days according to the Twelve Chinese Zodiac Animals called Junishi in Japanese. It is well-known that the Junishi is used to represent the year; however, in the past, days were commonly represented by the 12 zodiac signs: Rat (Nezumi), Ox (Ushi), Tiger (Tora), Rabbit (Usagi), Dragon(Tatsu), Snake (Hebi), Horse (Uma), Sheep (Hitsuji), Monkey (Saru), Rooster (Tori), Dog (Inu), and Pig(Buta); therefore, each animal day comes every 12 days.

Even in today’s world, where science and technology have advanced so much, Junishi are still used to represent times and directions, and in daily life, it is more commonly used for things like New Year’s cards and birth years, as we still say things like “This year is the Year of the Rat” or “I was born in the Year of the Ox.” I was born in the year of the Horse and my husband, Jon, was born in the year of the Rabbit.

Doyō no Ushi no Hi occurs multiple times a year

The term Doyō no Ushi no Hi is generally understood to refer to the Day of the Ox during the summer Doyō period despite the fact that the Doyō period occurs at the beginning of each season. So, there are multiple the Ox Days during the Doyō period throughout the year.

For example, the Days of the Ox during the Doyō period from 2024 to 2027 are:

• Days of the Ox in 2024
  January 26th, April 19th, May 1st, July 24th, August 5th, October 28th
• Days of the Ox in 2025
  January 20th, February 1st, April 26th, July 19th, July 31st, October 23rd, November 4th
• Days of the Ox in 2026
  January 27th, April 21st, May 3rd, July 26th, October 30th
• Days of the Ox in 2027
  January 22nd, February 3rd, April 28th, July 21st, August 2nd, October 25th, November
  6th

When counting the days according to the 12 Chinese zodiac signs, a full cycle lasts 12 days. The Doyō period lasts for about 18 days; therefore, during that time the Day of the Ox may occur twice in the Doyō period. In that case, the first Day of the Ox is called “Ichi no Ushi” and the second Day of the Ox is called “Ni no Ushi.” For example the Days of the Ox of the spring Doyō and summer Doyō in 2024 are:

Please note as the dates for the beginning of spring, summer, autumn, and winter vary every year, the period of Doyō and Ushi no Hi also differ from year to year.

Is it lucky to eat food that starts with “the sound of u” on the day of the Ox?

In Japan, it has been believed since ancient times that eating foods with the sound “u” on the day of the Ox is auspicious, and there has been a custom of eating foods with the sound “u” to pray for good health and freedom from illness. The reason why foods with sound “u” on the day of Ox have been eaten is because Ox is Ushi in Japanese, which is a wordplay with sounds. Playing with the sounds of words using the names of foods to bring good fortune is deeply related to food culture and customs in Japan.

As Doyō, which marks the change of seasons, is a time when people are prone to falling ill, people tend to eat foods which start with sound “u” in them. Some typical examples are udon (udon) noodles, うり(uri) like (cucumbers, water melon), pickled plums (ume), and beef (ushi). It probably makes sense to have a custom of eating those foods that are easy to digest and absorb, and that have the effect of relieving fatigue and replenishing energy on the Day of the Ox, the changing of the seasons.

The History of Eating Eel in Japan

Eels (Unagi), which start with the sound “u” in their name, were also perfect to eat on the Day of the Ox. Japanese people have been eating eels since early recorded history. Based on archeological evidence this goes back at least as far as the Jomon period 5,000 years ago.

There is more evidence of eel consumption in the oldest collection of Japanese poetry called “Manyoshu” compiled during the Nara period (the years from 710 to 794), there is a poem by Ōtomo no Yakamochi in which he writes,

“石麻呂(いはまろ)にわれ物(もの)申(まを)す。夏痩(やせ)の良(よ)しといふ物そ。鰻(むなぎ)取り食(め)せ”

The poem means that “I would like to tell Iwamaro that eel is good food for summer fatigue. Please have some eel”. From this poem, it seems that eels were recognised as an antidote to summer fatigue at least as early as the Nara period.

During the Edo period, as Tokugawa Ieyasu aimed to advance the development of Edo, eels came to inhabit the reclaimed wetlands created through land reclamation. As a result, eels became established as a common food for labourers.

If you are in Japan in summer, you can’t help but stop in front of some eel restaurant because of the very nice teriyaki smell. During this time you will see people buying cooked teriyaki eels in supermarkets before or after Doyō no Ushi no Hi. If you are not familiar with the tradition, you might start wondering why so many Japanese people are eating teriyaki eel dishes called “Unagi no Kabayaki (Grilled teriyaki eel)”, on the Day of the Ox during the midsummer period.

How did the Day of the Ox during the midsummer period become associated with eating eel?

Although the natural season for eels is from autumn to early winter when they store up nutrients in preparation for hibernation, the practice of eating eel on the midsummer day of the Ox began in the Edo period. There are various theories about why this tradition became established, but the most widely accepted one is that it was started by the scholar Hiraga Gennai (1728-1780).

He was the Japanese equivalent to Leonardo da Vinci who is known for many inventions, such as creating a small electrical generator or “Erekiteru” and a fire proof asbestos cloth! He learnt the read Dutch allowing him greater access to western textbooks.

For his role in the tradition relating to eating eel during the Day of the Ox, he became a pioneer of what we would now call an advertising copywriter. The story is that Gennai happened to enter an eel restaurant, where the owner who was having trouble selling eels in the summer consulted him, saying, “In the summer, the number of customers drops. Do you have any good ideas?” Gennai suggested putting up a sign that read “Today is the midsummer Day of the Ox,”, which was a sublte reminder to people that it is a good time to eat eel. This turned out to be a great success as soon many other eel restaurants followed this way. From just one enterprising restaurant owner selling eels on the summer day of Doyō no Ushi became widespread. In fact though, according to Maruyama Junichi, Editorial writer for the Yomiuri Newspaper, there are no actual historical records confirming that Gennai created the slogan “Eat eel on the midsummer day of the Ox”. So whether this is an urban myth or the truth, the one thing we are certain of is the tradition started in this period.

My childhood memory on the Day of the Ox in summer

The Day of the Ox in summer is special because my parents used to take my younger brother and me to an eel restaurant near our house. If you have been to Japan in summer, you will probably have noticed that it is so hot that people often experience summer fatigue and a loss of appetite. To boost their energy, people eat foods that enhance stamina. Since eels contain many nutrients that are useful for combating fatigue, my parents had us eat teriyaki eel dishes.

The restaurant had outdoor grills, and when we arrived, the smoky smell of grilling teriyaki eel whetted our appetite. We always ordered a teriyaki eel rice box, eel liver soup, and eel bone crackers. When I was little, I didn’t like eel liver, but the teriyaki eel rice box was delicious, and the salty eel bone crackers were very crispy—perfect with Japanese sake! I’m not quite sure whether I got rid of my summer fatigue after eating eel, but this is a summer tradition and it remains one of my treasured family memories of summer.

Japanese words related to the Day of the Ox in summer

Hope you have found this article of interest. In this and future articles I will finish by including some key Japanese phrases or words or study tips for your reference.

References

https://www.yomiuri.co.jp/column/japanesehistory/20220325-OYT8T50043

https://www.env.go.jp/garden/kokyogaien/news/2018/07/post_284.html

http://kic-update.com/text/5775/

https://digitaleye-edo.seesaa.net/article/504114310.html

https://wb.kirinholdings.com/about/activity/foodculture/06.html

https://www.cracked.com/article_30420_the-gay-electro-ronin-meet-hiraga-gennai-the-da-vinci-of-japan.html