Shortly after noon on December 15, 2025, a devastating fire at the private sauna "SAUNATIGER" in Akasaka, Tokyo, took the lives of a couple in their 30s. The victims were Masaya Matsuda, 36, who ran a hair salon, and his wife Yoko, 37, a nail artist, both from Kawasaki. They had a three-year-old child.

The venue was a members' luxury private sauna, with single visits starting at 19,000 yen and monthly plans ranging from 60,000 to 390,000 yen. It was overseen by Italian TV personality Girolamo Panzetta and known among celebrities. The Matsudas were first-time visitors, using a two-hour, 19,000-yen visitor plan.

The Double Safety Failure Behind the Tragedy

The site inspection revealed a shocking state of safety management.

When found, the sauna room's doorknob had come off on both the inside and outside and lay on the floor. The room had originally had an L-shaped wooden doorknob, which apparently detached, leaving the door impossible to open. The couple had collapsed near the door; investigators found traces of an attempt to break the glass with hot sauna stones wrapped in a towel, as well as subcutaneous bleeding on their hands from pounding on the door.

More disturbing still, although the emergency button inside had apparently been pressed, the receiver in the office had been switched off, so no call for help got through. The operator reportedly said the receiver had never once been turned on since opening. Staff noticed the fire from the alarm bell, but when firefighters arrived, the private room's door was still locked from the outside.

Later reporting revealed that more than six months before the fire, a customer had been briefly trapped in another room when a doorknob came off, and that an interior contractor had proposed switching to a knob-less push door for safety—a change the operator had not adopted. The Metropolitan Police are examining the management for possible professional negligence resulting in death. The cause of the fire remains under investigation, with possibilities cited including heater overheating and contact with a towel.

Japan's Third Sauna Boom

Behind this tragedy lies Japan's rapid sauna boom.

In Japan's sauna history, the 1964 Tokyo Olympics sparked a first boom, and the rise of "super sento" bathhouses in the 1990s a second. Now the country is in the middle of a "third sauna boom." The 2019 drama "Sado" spread the word "totonou" (to get balanced), and popularity exploded, especially among younger people.

Notable is the rise in fires. According to data presented by the Consumer Affairs Agency in June 2024 and other sources, almost no serious sauna fires were recorded over the 54 years from 1968 to 2022, yet five occurred in the three years from 2022. This is not unrelated to the surge in facilities.

Private saunas in particular, a new business model, carry safety challenges that differ from traditional public baths. Many have no staff on site, and inadequate emergency response has been pointed out.

Finland vs. Japan: Different Sauna Cultures

In Finland, the home of the sauna, sauna culture was inscribed on UNESCO's Intangible Cultural Heritage list in 2020. For a population of about 5.5 million, there are said to be more than 3 million saunas, and having one at home is common.

Finnish saunas run at relatively lower temperatures of around 80–90°C and emphasize humidity control through "löyly." Users pour water on the stones themselves to adjust the steam, and the sauna is enjoyed as a place for socializing with family and friends. With electric heaters widespread, temperature can be managed at the flick of a switch.

Japanese saunas, by contrast, tend toward high heat (90–100°C and above) and low humidity. The style pursues the "totonou" sensation through the contrast with a cold plunge. This extreme temperature swing has its benefits but makes facility safety management all the more important.

Global Sauna Safety Standards and Japan's Challenges

There is no unified international safety standard; the matter is left to each country's building codes and public-bath laws. In Europe, products must carry CE safety certification, with temperature controls and overheat protection as standard.

In Japan, public-bath and fire-service laws apply, but the private sauna as a new business type was not fully anticipated by existing rules. This accident exposed gaps in door structure and maintenance, inspection of emergency buttons, response when no staff is present, and safety review at opening. In response, the Ministry of Health, Labour and Welfare notified local authorities nationwide to survey the safety management of sauna facilities.

Safety Checks Users Can Perform

The accident points to steps users themselves can take.

Before using a facility, it is worth checking that the door opens properly from the inside, along with the location of the emergency button, the evacuation route, and whether staff are present. During use, keeping towels and flammables away from the sauna stones, leaving without pushing yourself if you feel unwell, and avoiding long stays in an enclosed room are basics that help protect you.

The Future of Japan's Sauna Culture

The sauna boom is a cultural phenomenon born of health consciousness and the need for relief in a stressful society. New ways to enjoy it, such as tent saunas and saunas at glamping sites, are spreading too.

Yet this fire laid bare the reality that safety management had been left behind amid rapid expansion. An industry-wide review of safety standards, regular inspections, and staff training are urgent. Saunas offer great benefits for refreshing body and mind—which is exactly why the culture can endure only on a foundation of safety.

Tell Us About Sauna Culture in Your Country

In Japan, this tragic accident happened in the midst of the third sauna boom. Does your country have a sauna culture? What are the safety standards like? Whether you come from a culture where homes have saunas, as in Finland, or from the U.S., Asia, or elsewhere with a different tradition, we'd love to hear your perspective.