Onsen in Japan: A Cultural Guide to Natural Hot Springs

Many Westerners are uncomfortable with anyone seeing their naked bodies, but being naked with friends and strangers is a traditional practice in Japan.

It happens every day in hot springs across Japan, as it has for thousands of years. Bathing together is a healthy, relaxing, and bonding experience.

A special kind of platonic friendship develops when people do not hide behind their clothes. In Japanese, this relationship is called hadaka no tsukiai.

People tend to shed their pretensions when they remove their clothes. The only cloth that bathers may bring into most hot springs is a small towel that barely covers the private parts.

Onsen and Japanese culture

The tradition of onsen bathing is deeply ingrained in Japanese culture. Originally established as health retreats, these hot springs have evolved into a top tourist draw and significantly shaped the country's bathing practices. Families, couples, and friends often embark on weekend getaways to onsen towns—locations with a high concentration of hot springs and bathing facilities—to indulge in the healing waters and escape the stresses of daily life.

Health benefits of onsen

Onsen have long been revered for their restorative properties, with the mineral-rich waters offering myriad health benefits. The heat of the water, which must be at least 25°C to be classified as an onsen, promotes blood circulation and increases the body's metabolism.

The absorption of minerals through the skin is thought to further enhance onsen's positive effects. Sulfur may aid in treating skin conditions like eczema or psoriasis, while carbonic acid can lower blood pressure. Many onsen are lauded for their ability to soothe aching muscles, alleviate joint pain, and promote better sleep.

Soaking in an onsen also offers mental health benefits. The serene atmosphere and calming ritual of bathing can melt away stress, providing a meditative and rejuvenating experience that refreshes both body and mind.

Types of onsen and their unique mineral compositions

Japan's onsen are classified into various types based on their mineral composition. The 19 designated chemical elements that define an onsen each offer different health benefits, colors, and even smells to the waters.

Some of the most common onsen types include:

• Sulfur onsen (硫黄泉): Known for their distinct odor and milky appearance, they are believed to aid in treating skin conditions and arthritis.
• Sodium chloride onsen (ナトリウム泉): These baths have a salt content similar to seawater and are said to promote heat retention and alleviate muscle pain, cuts, and burns.
• Iron onsen (鉄泉): These onsen are characterized by a rusty color and are thought to combat anemia when consumed.
• Carbonated onsen (炭酸泉): Naturally bubbly and feels soft on the skin, offering benefits for skin ailments.
• Radium onsen (ラジウム泉): Contain trace amounts of radioactive elements that may help lower blood pressure and relieve gout or circulatory issues.

The combinations of minerals in each onsen create unique soaking experiences and are frequently advertised as part of their allure.

Rules and customs to follow in an onsen:

Onsen follow strict codes to ensure a pleasant and respectful experience for all users. Here are a few essential rules:

• Washing before bathing: Before plunging into an onsen, it's crucial to wash thoroughly. Use shower stations equipped with stools and personal showers to clean yourself with soap and hot water.
• Avoid plunging into the water too quickly: Onsen water is hot, and rapid immersion can be difficult. Enter gradually to allow your body to get used to the temperature.
• Don't submerge your head underwater: In an onsen, it's important to keep your hair out of the water. If you have long hair, tie it up to prevent it from touching the water.
• Avoid talking too loudly: Respect for quiet is paramount in an onsen. Keep quiet and calm so as not to disturb others.
• No swimwear allowed: It is possible to keep a small cotton towel in the onsen, called a tenugui. No towel should be in contact with the bathwater. This keeps the water particularly clean.
• Rinse off after bathing: Rinsing is recommended for certain types of mineral composition. A quick wash will get rid of the acid, hydrogen sulfide and other minerals present in some waters, especially if you have sensitive skin.

Other rules of etiquette or tips to know!

• Photography prohibited: It's strictly forbidden to take photos. If you want to take some nice souvenir shots, reserve a private onsen for that purpose!
• Don't drink alcohol: Excessive heat can lead to overheating and discomfort.
• Take off your jewelry: Certain minerals can damage some types of metal. 
• Bring cash: As in many places in Japan, cards are not accepted, so remember to give change, which can also be used at the lockers.
• Pregnancy: It’s strongly advised against going to onsen, where the water temperature often exceeds 40°C, which is very bad for the heart and circulation. Sentos, on the other hand, offers a wider choice of baths. Just be careful of staying in too long and baths hotter than 37°C.

Where to enjoy onsen: ryokan, hotels, and public bathhouses

Onsen can be enjoyed in various settings, from traditional ryokan inns to modern hotels and public bathhouses. For the quintessential onsen experience, staying at a ryokan is highly recommended. These Japanese-style inns often feature on-site hot spring baths, allowing guests to soak at their leisure. Some ryokan even offer private open-air baths connected to guest rooms for the ultimate in privacy and luxury.

Many hotels and resorts in onsen towns also boast their own hot spring facilities, catering to visitors who prefer more Western-style accommodations. These range from simple baths to extensive spa complexes with multiple pools, saunas, and massage services.

For a more casual experience or day trip, public bathhouses (銭湯, sento) are a great option. Found in most cities and towns, sento offer a chance to soak in onsen waters without the need for overnight stays. Some popular onsen towns like Kinosaki even provide passes that allow visitors to hop between several different public baths to sample a variety.

Top onsen destinations in Japan

Japan abounds with onsen towns, each offering its own unique charm and specialties. Some of the most renowned destinations include:

• Kusatsu Onsen (Gunma): Known for its high-volume, highly acidic springs and iconic yubatake, where the water is cooled.
• Beppu Onsen (Oita): The steam stacks of the onsen can be seen when heading into town. One of the most famous destinations in Kyushu. 
• Hakone (Kanagawa): Easily accessible from Tokyo, offering stunning views of Mount Fuji from its many outdoor baths.
• Kinosaki Onsen (Hyogo): A picturesque town with seven public bathhouses and a charming, traditional atmosphere.
• Ginzan Onsen (Yamagata): A secluded, historical town with ryokan lining a river, creating an enchanting ambiance.
• Dogo Onsen (Ehime): One of Japan's oldest hot springs with an iconic, three-story bathhouse said to have inspired Studio Ghibli's "Spirited Away."

These are just a few of the many onsen destinations waiting to be discovered, each promising a rejuvenating escape and a deep dive into one of Japan's most cherished traditions.

Onsen and tattoos

Many ask about the accessibility of onsens for visitors with tattoos, and indeed, due to certain stigmas, among other reasons, it is a valid question. Many onsens do not allow visitors who have prominent tattoos, especially if they are unable to be hidden away or covered. 

However, this is not always the case, and finding a tattoo-friendly onsen often requires just a bit of research. 

• Onsen that accept tattoos: More and more onsen, especially in big cities like Tokyo and Kyoto, are beginning to relax this rule. Some establishments even have specific policies allowing tattooed guests access to designated areas.
• Solutions for people with tattoos: If you're tattooed and want to enjoy an onsen, it's possible to find establishments that allow tattoos or offer tattoo covers to wear for the occasion. It is therefore essential to check onsen policies in advance.

Combining onsen visits with other Japanese cultural experiences

A visit to an onsen can easily be combined with other quintessential Japanese experiences for a well-rounded and immersive trip. Many onsen towns offer opportunities to don traditional clothing such as yukata (lightweight kimono) and geta (wooden sandals) while strolling the streets lined with old-fashioned shops and restaurants.