The kotatsu was first conceptualized during the Muromachi period in the 14th century. This was at first a wooden table with a blanket or komono draped over a sort of fire pit, or irori, lined by bricks and sunk into the floor. This would contain the fire and allow for the embers to burn allowing the area under the blanket to trap the heat. This may sound dangerous, but the fires were supposed to be kept low so they would not turn hazardous. This full table at the time was known as a hori-kotatsu. The kotatsu was later revolutionized during the Edo period in the 17th century. They raised the fire so that the kotatsu was more portable. The modern look of the kotatsu was not invented until the 19th century. This was lower than the previous kotatsus and the hearth was slightly lower than ground level. There were many health and safety issues at this point in the kotatsu’s history and many children died from carbon monoxide poisoning.

Modern kotatsus pose much less of a risk. They are traditionally heated using infrared lights rather than charcoal. This allows the guests to not be burned while using their kotatsus as well as not being poisoned by the noxious fumes released from the fire. Tatami mats continue to be put under them for comfort while sitting and do not pose a fire hazard with the modern day lights. Kotatsu have become increasingly popular since their existence has been spread through anime and other media. This convenient table is a safe and easy way to enjoy the winter chill all while sipping a nice cup of tea with your family.