Modern Kotatsu: Japan’s Way of Staying Warm in Winter

Modern Kotatsu: Japan’s Way of Staying Warm in Winter

Want more UJ? Get our FREE newsletter 

Need a preview? See our archives

Woman under a kotatsu
Picture: Fast&Slow / PIXTA(ピクスタ)
It's kept Japan warm for over 500 years. So why is it disappearing from Japanese homes? A short history of the kotatsu (and how to buy one).

Occasionally, I review what we’ve written on Unseen Japan to see what gaps exist. Recently, during a recent review, I was shocked – shocked! – to discover we’d never done a piece on the classical and modern kotatsu (炬燵).

If you’ve ever been to Japan, you know what I’m talking about. Like heated toilet seats, the kotatsu is one of those Japan-specific conveniences that you find yourself yearning for when you leave. In this article, I’ll introduce the device, look at its history, and even tell you where you can buy them outside of Japan.

What’s a Kotatsu?

Woman under kotatsu
Picture: JADE / PIXTA(ピクスタ)

The idea behind the kotatsu is pretty basic. It’s essentially a table (specifically a wooden frame called a yagura; 櫓) with a heater element on its underside. A futon comforter cover rests under the table’s surface. The comforter itself provides warmth but also traps the heat inside. The result? A toasty warm place to watch TV, read books, or count the cracks in the ceiling on cold Japanese winter nights.

There are two basic types of kotatsu. The oki-kotatsu (置きこたつ) is simply a yagura frame that exists at the same level as the floor. But homeowners can also opt for a hori-kotatsu (堀りこたつ), in which the device is placed above a hole in the floor in which users place their legs.

The yagura frames also come in many shapes and sizes [1]. The table, for example, can be either rectangular or round. People with back issues can also buy seats that are specifically made to fit under the warm table.

A 500-Year History

The exact origins of this unique furniture piece are a mystery of history. However, they seem to have initially appeared in Japan’s Muromachi Era (1336 – 1573) [2]. Some historians speculate that the device was ideal for staying warm in houses that were generally designed to stay cool in the summer.

The initial Muromachi era kotatsu were fueled by a sunken fireplace, or irori (囲炉裏). In the Edo Era, we see the first appearance of the hori-kotatsu, then known as the koshi-kake gotatsu (腰掛けごたつ).


Of course, in the modern era, few people want to risk death by carbon monoxide poisoning. So starting in the Taisho Era, electric models made their appearance. After World War II, the electric model became the standard. The device shot up in popularity around this time as single-use models and other varieties widened their mass appeal.

Unique to Japan (Sort Of)

The modern kotatsu is often seen as a quintessentially Japanese good. And in some ways, it is: kotatsu fever never really spread out of Japan to neighboring Asian countries like Korea. However, similar devices exist throughout the world:

  • The korsi [3], which is used in Iran;
  • The foot stove (voetenstoof) [4], a Dutch and North German device for keeping one’s legs warm that also saw some use in the United States;
  • The Spanish brasero, a type of heater placed under blanketed table;
  • The mesa camilla [5], another Spanish invention very similar to the kotatsu.

All this goes to show that you can’t stop the power of a good idea!

Is the Modern Kotatus Losing Popularity?

Recent evidence shows that affection for the furniture piece may be waning. Share on X

Most people, in and outside of Japan, see the kotatsu as a staple of Japanese winters. However, recent evidence shows that affection for the furniture piece may be waning.

A 2018 article on Japanese site MoneyPost cites dropping sales figures for the devices in recent years. In 1990, there were over 1.78 million in Japan. By 2003, that number had dropped to a mere 247K. The drop was so precipitous that the Japanese Electrical Manufacturer’s Association hasn’t published updated numbers since then.

Why the こたつ離れ (kotatsu-banare; flight from kotatsu)? Part of the answer might lie in the aging of Japan’s population. People interviewed by MoneyPost said that, as they get older, cleaning the futon and bringing it out every winter becomes a pain. Additionally, older people can’t as readily sit down and get back up from the floor as they once could.

Modern Kotatsu: Used More in Okinawa Than Hokkaido?!

Wanna hear another surprising stat? In 2017, Weather News ran a survey on the use of the modern kotatsu in Japan. Their goal: identify the prefectures where it was most used. The result was counterintuitive: kotatsu are used least in the coldest climes in Japan! Only 23% of the residents of Japan’s northern island, Hokkaido, report using one. In fact, more people in Okinawa – 30% – than residents of Hokkaido report using one. That’s pretty shocking, especially when you consider that Hokkaido is home to Japan’s coldest temps. (Temperatures in Asahikawa can fall as low as -41C in the winter.)

Only 23% of the residents of Japan's northern island, Hokkaido, report using a kotatsu. Share on X

Overall, the survey found that 52% of respondents used kotatsu. The device is most popular in Yamanashi and Fukushima prefectures (75% and 72%, respectively). Only 26% of respondents reported the furniture as their preferred method of staying warm. Some 36% of respondents instead say that they used the heating element in their homes’ air conditioner unit instead. Another 26% reported preferring a gas or oil stove. In fact, a whopping 83% of Hokkaido residents prefer the latter option over a kotatsu.

Buying Modern Kotatsu Outside of Japan

Don’t let this trend dissuade you, however. As anyone who’s been to Japan will tell you, a kotatsu is a near indispensable ally against the winter cold. Plus, it’s a great refuge for your cats…

Unseen Japan on Twitter: “More kotatsu kitties. Looks like they picked up a new party member… / Twitter”

More kotatsu kitties. Looks like they picked up a new party member…

Don’t live in Japan? Don’t worry! Several manufacturers of modern kotatsu make their products available on Amazon and through other retailers for a worldwide audience. This means that you can enjoy the comfort and coziness offered by a kotatsu no matter where you live.

Here are some of the best-rated deals I found on Amazon.

(Note: Links below are affiliate links; UJ earns a commission if you treat yourself to a sweet new kotatsu. Availability is based on the US site – check your regional Amazon site for availability and shipping options. Also, check reviews/products descriptions – depending on the product and where you live, you may also need to buy a voltage converter.)

Yamazen Casual Kotatsu

The Yamazen products are by far the best-selling products on Amazon Japan. This particular product is very reasonable priced at around US $213. Note, however, that it doesn’t ship with a futon – you have to buy it separately. (Several good quality comforters are listed in the related products section.)

AZUMAYA Folding Legs Wooden Kotatsu Header Table

Sitting at a handsome 4.7 star review currently, the AZUMAYA table sports folding legs. A great attribute for people in tight spaces or anyone who simply wants to put the kotatsu away for the winter.

Buying Modern Kotatsu in Japan

If you currently live in Japan, your options are even better. In fact, Amazon Japan helps you out with this list of the top-selling kotatsu in the country. Of course, if you’re in-country, you can also buy one directly from a local furniture retailer.


Kotatsu might not be as popular as they once were. But for Japan lovers who miss their warmth on cold winter nights, they still hold a certain magic.

Japanese Kitchen Knives: Like Katanas for Your Kitchen


[1] こたつの選び方. Kakaku

[2] 【 起源は室町時代 】日本の冬の風物詩・こたつの歴史500年. Rekijin

[3] Korsi. Wikipedia

[4] Foot stove. Wikipedia

[5] La mesa camilla. Allie in the South of Spain

Want more UJ? Get our FREE newsletter 

Need a preview? See our archives

Jay Allen

Jay is a resident of Tokyo where he works as a reporter for Unseen Japan and as a technial writer. A lifelong geek, wordsmith, and language fanatic, he has level N1 certification in the Japanese Language Proficiency Test (JLPT) and is fervently working on his Kanji Kentei Level 2 certification.

Japan in Translation

Subscribe to our free newsletter for a weekly digest of our best work across platforms (Web, Twitter, YouTube). Your support helps us spread the word about the Japan you don’t learn about in anime.

Want a preview? Read our archives

You’ll get one to two emails from us weekly. For more details, see our privacy policy