Tokyo’s Minato Ward Requires Sauna Emergency Buzzers After Inspectors Found One in Eight Had None

Every sauna in Tokyo’s Minato ward now needs an emergency buzzer that bathers can reach from inside, a check that it works while the sauna is open, and a door they can open easily with no latch. The ward assembly passed the rules unanimously on October 9, and they took effect on October 13.

They answer the fire of December 15, 2025, at SaunaTiger, a private-room sauna in Akasaka, in which a couple in their 30s died. The sauna’s L-shaped wooden door knobs were found detached on the floor, after being replaced earlier that year because of cracks and looseness. The emergency button inside showed signs of being pressed hard, but the operator’s president told police he had never switched on its receiver in the office since taking over the business about two years earlier, Jiji Press reported.

Existing saunas have until September 2027 to comply

The changes amend the two ordinances under which Minato licenses saunas, one for public baths and one for hotels and inns. Operators must:

• put an emergency buzzer where bathers inside can easily use it;
• inspect the buzzer regularly and confirm it works while the sauna is in use;
• fit a door that bathers inside can open easily, with no latch or other hardware that could shut them in;
• have a system for responding quickly to an accident or other emergency;
• show the room temperature on a thermometer and give staff a window or other way to see inside.

The thermometer and window rules were already in force for the ward’s “other public baths,” the licence class that includes standalone saunas. The buzzer, door and emergency-response rules are new.

Existing saunas have until March 31, 2027 to fix their doors and until September 30, 2027 to install and test buzzers. A sauna built, enlarged or altered after October 13 gets no grace period. The ward said in an August 31 statement that it will use administrative measures, including improvement orders, against facilities that still haven’t complied once the grace period ends.

One in eight Minato saunas had no buzzer

The ward and the Tokyo Fire Department inspected all 125 saunas it licenses between January and April 27, 2026, and published the results on July 28:

• Buzzers: none at 16 facilities (12.8%), including 13 of the 57 with private sauna rooms. Eight of the 109 buzzers didn’t work.
• Doors: latches at 16 facilities, and inward-opening doors at 10.
• Staff checks: no staff patrols at 58, including 54 of the 57 private-room facilities.

The ward judged that none of the 16 without a buzzer was in immediate danger, because their doors had no latch and opened outward, had a latch on a door in good working order, or had frequent staff patrols. It told them to install buzzers promptly and the eight with broken ones to fix them.

The Akasaka room fell between two national guidelines

Minato had licensed SaunaTiger as a hotel or inn in July 2022. Japan’s national hygiene guideline for public baths already called for an emergency buzzer in the sauna room. The guideline for hotels and inns didn’t mention one, the health ministry noted in an April 21 notice to local governments.

The ministry’s nationwide count, taken as saunas close in on the number of Japan’s sento, found saunas at 5,240 hotel and inn facilities and 7,812 public baths. Buzzers were installed at 63.5% of the hotels and inns and 85.8% of the public baths. The ministry stopped short of a national mandate. It asked local governments to tell hotel and inn operators that a buzzer can serve as an emergency safety measure, and to guide those that need one. Minato wrote the requirement into both of its ordinances.

The Tokyo Metropolitan Government, which oversees saunas in the parts of Tokyo outside the 23 wards and the cities of Hachioji and Machida, checked 42 private-room saunas there this year. Twenty-five had no buzzer or intercom, but the government judged all 42 to have safety measures suited to their circumstances, and proposed no new rule.

It wasn’t the first time a knob had come off at SaunaTiger. The president told police he had asked the former president to switch to push-open doors and was turned down because the rooms would no longer be airtight, Jiji reported in February. In spring 2025, an inside knob came off in another of the shop’s rooms and briefly trapped a customer until an acquaintance outside opened the door. Police searched sites linked to the operator, Sauna & Co., in December and the former president’s company in February, on suspicion of professional negligence resulting in death. No charges had been reported by late October, and the cause of the fire hasn’t been made public.

Barrel and tent saunas got their own fire-code class

A separate national change, unrelated to the fire, took effect on March 31. Japan’s Fire and Disaster Management Agency created a class of “simple sauna equipment” for heaters in outdoor tent or barrel saunas, rated at 6 kW or less and fired by wood or electricity (FDMA notice, November 12, 2025). The agency said simple outdoor setups had multiplied with Japan’s recent sauna boom. Public comment closed in August 2025, four months before the Akasaka fire.

• Shutoff: the heater needs manual and automatic cutoffs for overheating. A wood-fired unit can have a fire extinguisher within quick reach instead, and needs a noncombustible ash catcher.
• Clearances: set by performance, not fixed distances. Nearby combustible material must stay at or below 212°F, or not ignite.
• Notice: operators tell the fire department, as with other saunas. A private person’s own unit is exempt; a sole proprietor’s business unit isn’t.
• Limits: a barrel or tent with more than one heater doesn’t qualify, tents need anchoring against tipping, and units shouldn’t be fired in strong wind, under the agency’s operating guidance.

Cities adopt the class through their own fire ordinances. Chiba and Sagamihara did on March 31. Tokyo’s metropolitan assembly passed its amendment this fall, after Governor Yuriko Koike submitted it on September 18. For the US code questions around portable saunas, see our report on the rolling smoke-sauna heater.

Minato’s rules work as a checklist for private sauna rooms

Any operator renting private sauna rooms can run the same checks Minato’s inspectors did:

• Is there a buzzer the bather can reach from the bench, and does it sound somewhere staff will hear it?
• Was it tested today, with the receiver switched on?
• Does the door open from inside with no latch, and does it open outward? Minato counted inward-opening doors as a finding.
• If the handle comes off, can the door still be opened from inside?
• Does someone check the rooms during bookings, and does every shift know what to do when the buzzer sounds?

For the US side of the question, a white paper argued this year that American sauna operators need a standard of their own.