Tokyo Toshima City
Sauna & Hotel Karumaru Ikebukuro
One of the Kanto region’s largest sauna hotels, with four saunas and four cold plunges
- Wood-fired sauna
- Kelo Wood
- Aufguss available
- Self löyly available
- Auto löyly available
- Finnish sauna
About Sauna & Hotel Karumaru Ikebukuro
Sauna & Hotel Karumaru Ikebukuro is a men-only sauna and hotel complex in Ikebukuro, Toshima-ku, Tokyo. Its baths, said to be among the largest in the Kanto region, have four saunas: a rock sauna of Aji stone, a kelo sauna (kelo, the silver-aged pine Finns call the jewel of wood), an herbal steam sauna and a wood-fired Finnish sauna. Four cold plunges in steps, from ultra-cold water below 10°C (50°F) to a resting temperature of about 33°C (91°F), let you cool down, and there are also a carbonated bath, an electric bath, a rock bath, a masu box bath, an open-air jacuzzi and more. With a dining area, unlimited manga, recliners and a coworking space where you can spend the whole day, it is the pinnacle of urban saunas.
BathBATH
Carbonated bath
A carbonated bath with carbon dioxide dissolved artificially to reach a high concentration on a par with a therapeutic spring. It is based on a traditional bathing therapy long called “the bath of the heart” in Europe, and better circulation, relief from chills and recovery from fatigue can be expected. Because the concentration is high, it is deliberately made with few bubbles, and its hallmark is the sensation of carbonation seeping slowly into the skin. The electric bath is set inside this carbonated tub, so you can enjoy the benefits of both at once.
Electric bath
A new kind of electric bath with three types of stimulation, as in a massage chair: pressing, kneading and tapping. The current is said to regulate the body’s ions and make the muscles contract, improving circulation. It sits inside the carbonated tub, so the penetrating effect of the strongly carbonated bath and the electrical stimulation work at the same time. How strongly you feel the stimulation varies greatly with your physical condition, so those with chronic illnesses should take care.
Rock bath
A rock bath of Kitagi stone, one of the three famous stones of the Seto Inland Sea. It is set to the skin-temperature range close to human body temperature, and by keeping energy use to a minimum it acts on the parasympathetic nervous system, bringing deep relaxation. Kitagi stone, used since the Edo period in famous buildings such as Osaka Castle, the Bank of Japan and Tokyo Station, feels smooth and refined to the touch. Feeling neither hot nor cold blurs the boundary of the body, for a soak that feels like floating.
Masu box bath
A one-person square box bath made lavishly of Aomori hiba, from one of Japan’s three most beautiful forests. Aomori hiba, also called “golden wood” because it glows gold as the years pass, wraps you in its beautiful grain and a refined scent like wandering into a forest. In a completely enclosed space for one, away from the bustle of the sauna crowd, you can take your time and enjoy a moment all your own.
Open-air jacuzzi
An outdoor jacuzzi built of fine black granite. With the pleasant stimulation of the bubbles, you get the luxury of feeling the sky over central Ikebukuro directly on your skin. In summer the temperature may be lowered so it can be used as an Open-Air Cool-Down Bubble Bath. The contrast between the city air and the warm water creates a distinctive relaxation, and it adds an accent to the cycle of sauna and bath.
SaunaSAUNA
Rock sauna
A dynamic five-tier sauna with walls clad entirely in Aji stone, a rare and prized stone also called “the diamond of granite.” About 600 kg of sauna stones store and release heat, and its hallmark is a soft, enveloping heat that warms you slowly to the core. Humidity is on the high side, and each time the automatic löyly runs every 30 minutes, the temperature and humidity in the room jump at once. Staff aufguss by Karumaru’s aufguss team is held mainly in this sauna, on a regular schedule and packed every time. With five tiers, you can also settle in at the temperature you like.
Kelo sauna
A modern room built generously of kelo, the standing deadwood of European red pine over 200 years old. Its design, alternating the heartwood and the bark of the kelo, is one of a kind, and it is known as a kelo sauna found nowhere else in Japan. The rich scent unique to kelo drifts through the dim, calm room, and the heat stays in a dry, high range. Löyly you pour yourself is possible once every 15 minutes, and the scent comes alive the moment the steam rises.
Wood-fired sauna
A sauna with a wood-burning stove in the authentic Finnish tradition, said to be the only one in a major metropolitan area. The light of flickering flames, the crackle of firewood, the fragrance of wood and a soft heat like a sunny spot wrap all five senses. The heat from the METOS iki wood stove is a warmth in a different league from that of an electric stove, and löyly is sometimes poured when wood is added, about every 20 minutes. Time spent watching the flames and tending the fire is popular as the experience closest to “nature” among urban saunas.
Herbal steam room
A barrel steam room. Nine or ten kinds of precious medicinal herbs gathered on Mount Ibuki in Shiga Prefecture, known as a “treasure house of medicinal herbs,” including Ibuki thyme, Elsholtzia and kuromoji spicebush, are simmered slowly, and you bathe your whole body in their steam. The temperature is about 50°C (122°F), but you are constantly wrapped in steam, so it feels very hot, and the scent and components of the herbs penetrate the whole body through the nose and mouth. The quiet space enclosed in a barrel of koyamaki (Japanese umbrella pine) is for one person only, for a focused experience all your own.
Cold BathCOLD BATH
Thunder Tornado
An ultra-cold plunge below 10°C (50°F) with swirling jets, a shock as if struck by lightning. The powerful current, churning like a tornado, amplifies the cold further, and within seconds a jolt runs through you that sets your whole body shivering. At 100 cm (3.3 ft) deep, it is deep enough to submerge yourself completely. The sharp chill may be bewildering the first time, but once you are used to it, it is so addictive that other cold plunges feel lacking. After the plunge, plenty of cool-down areas await indoors and out.
Yasuragi
A gentle bubbling cold plunge at about 25°C (77°F) that even those who dislike cold plunges can enter without worry. Step in after chilling to the core in the ultra-cold Thunder Tornado, and the soft bubbles and mild water together release the tension from your whole body and wrap you in a distinctive sense of bliss. At 60 cm (2 ft) deep, it is easy to get into, and ideal for alternating cold with cold together with Thunder Tornado.
Shoten
A jet cold plunge at about 33°C (91°F), conceived as the “rest” in “sauna → cold plunge → rest.” In this finely judged range, colder than skin-temperature water and warmer than Yasuragi, pleasant jets reach each part of the body, bringing a bliss like ascending to heaven. The front seats send jets to the lower back and soles of the feet, the back seats to the lower back and thighs, a distinctive design that lets you use it not just as a cold plunge but as an extension of totonou. At 40 cm (1.3 ft) deep, it is shallow and suited to long stays.
Acrylic Avanto
A one-person cold plunge that recreates the avanto, Finnish for “a hole cut in a frozen lake,” in a clear acrylic cylindrical tub. It stands in the rooftop area for cooling off in the open air and gives the unusual sensation of lowering yourself into a hole in the ice. At 100 cm (3.3 ft) deep, it is deep enough to submerge yourself completely. Its setting, with the scenery outside visible through the clear walls, is entirely different from the other cold plunges, and by giving wood-fired sauna users priority, it recreates the original way of using an avanto in the middle of the city.
Stay here
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Facility Information
- Address
- 6F, 2-7-7 Ikebukuro, Toshima-ku, Tokyo
- Business Hours
- 11:00〜10:00
Irregular Holidays
- Closed Days
- Irregular Holidays
- Gender Access
- Male Only
- Tattoo Policy (Communal Bath)
- No Tattoos
- Official Website
- View official site
Access
By train and bus
- Shinjuku Station: about 5 minutes
- Shibuya Station: about 11 minutes
- Tokyo Station: about 16 minutes
- Shinagawa Station: about 27 minutes
- Haneda Airport: about 60 minutes
- Narita Airport: about 90 minutes
30 seconds on foot from Exit C6 at the West Exit of Ikebukuro Station (JR Yamanote Line and Tokyo Metro). Take the elevator to the right of the entrance to Gusto Ikebukuro Nishiguchi on the ground floor up to the sixth-floor reception. Note that the dedicated elevator cannot be seen from the street outside. If coming by car, use a nearby parking lot
Visited by the Editor-in-Chief
The Editor-in-Chief visited in person in December 2025
No Match for the Thunder Tornado
Read the full review
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