Winter in Japan is cold.

Of course, winter is supposed to be cold, but what makes Japan’s winter particularly brutal is that the cold doesn’t stop at your doorstep—it follows you right into your home.

 

One major reason for this lies in Japan’s traditional architecture.

Given Japan’s humid climate, wooden structures became the norm. While these wooden houses provide excellent ventilation and keep the summer heat at bay, they also allow icy drafts to sneak in during winter, making indoor life just as frigid as the outdoors.

Unlike stone or brick houses with high insulation, Japanese homes have long embraced the reality that “winter means being cold—inside and out.”

 

To survive this merciless cold, the Japanese invented the kotatsu.

Long ago, our ancestors, ever resourceful, devised this compact heating device as an efficient way to keep warm with minimal fuel.

 

The kotatsu has made countless appearances in Japanese literature and anime, but for those unfamiliar with it, even the word itself might sound exotic.

Simply put, a kotatsu is a uniquely Japanese piece of furniture: a low table with a heater mounted underneath, draped with a thick quilt to trap the warmth.

 

Without a doubt, the kotatsu is a defining feature of winter in Japan.

Imagine slipping your legs under the table, only to be greeted by a gentle, enveloping warmth—like a magical cocoon that soothes your frozen body. Once inside, you are no longer bound by the mundane realities of everyday life. You have entered a winter paradise.

 

But beware—this paradise comes with a cost.

There is something devilishly seductive about the kotatsu.

Today, let’s uncover its history and explore the irresistible temptation it presents.

 

The History of Kotatsu

 

The origins of the kotatsu trace back to the Muromachi period (14th century).

At that time, the kotatsu was simply a wooden frame placed over a sunken hearth (irori), covered with a blanket to trap the heat from the burning coals. This brilliant idea quickly spread as a way to stay warm during the harsh winter months.

 

By the Sengoku period, a more portable version of the kotatsu emerged, using a brazier instead of a fixed hearth. Then, in the Edo period, the kotatsu evolved into a form closer to what we know today, with heated charcoal placed in a pot under the table.

 

When I was a child, my grandparents still used a mame-tan (bean-shaped charcoal) kotatsu, and I fondly remember my grandmother lighting the charcoal every winter morning.

oday, such scenes have mostly faded, replaced by the safer and more convenient electric kotatsu.

 

The Devilish Temptation of Kotatsu

 

Originally designed for warmth and efficiency, the kotatsu has, in modern times, gained a different reputation: the ultimate symbol of laziness.

 

But why does the kotatsu have such a powerful hold over people?

 

The answer is simple—its comfort is overwhelming.

 

The moment you slide your feet in, the cold that had gripped your body melts away. A deep, almost primal sense of security washes over you, as if you’re being wrapped in the embrace of a warm futon.

And once you’re in, stepping out again becomes nearly impossible.

 

One of the most iconic scenes of a Japanese winter involves a kotatsu and mikan (mandarin oranges).

 

A staple of Japanese culture, this combination is practically a national tradition. Piling up orange peels while lounging under the kotatsu is, arguably, its most authentic use.

 

But there’s a dark side to this bliss.

Yes, the kotatsu ruins people.

 

Once you get in, it’s over. Hours disappear in the blink of an eye.

 

Getting out of a kotatsu requires tremendous willpower—something few possess. This, my friends, is why the kotatsu is often described as “devilish.”

You sit down to watch TV, only to find yourself slowly lying down… Then, before you know it, you’ve drifted off to sleep. The kotatsu steals away not just your warmth, but also your motivation, ambition, and productivity.

 

 

 

It’s Not Just Humans Who Fall for the Kotatsu

 

Humans aren’t the only ones seduced by the kotatsu.

A famous Japanese children’s song, Yuki ya Konkon, describes the difference between dogs and cats in winter:

 

“Dogs joyfully run around outside, while cats curl up inside the kotatsu.”

 

In general, cats hate the cold, so this image makes perfect sense. But in reality, even dogs—who are supposed to love the snow—end up succumbing to the kotatsu’s warmth.

In fact, kotatsu for pets now exist.

 

It’s both absurd and hilarious, yet perfectly illustrates the kotatsu’s magnetic pull.

 

 

The Modern Kotatsu: Evolving Temptations

 

The kotatsu has stood the test of time, but it hasn’t remained stagnant. The modern kotatsu has evolved to fit changing lifestyles:

 

• Single-person kotatsu, perfect for tiny apartments
• High-table kotatsu, for those who prefer sitting on chairs
• Wearable kotatsu, allowing you to stay warm even while working

 

That being said, due to urbanization and the spread of central heating, more and more Japanese households—especially in the cities—are giving up on the kotatsu.

 

And yet, for many Japanese people, the word “kotatsu” still evokes nostalgic memories of family gatherings in a countryside home.

At grandma and grandpa’s house, the kotatsu was always there, a natural centerpiece where the family came together. People huddled inside, sharing a hot pot, peeling mikan, and chatting for hours.

 

Kotatsu: A Symbol of Laziness, or the Essence of Winter Happiness?