Your Ultimate Guide to Japanese onsens (hot spring bathing)

If you’re a traveller hoping to embark on a journey to the heart of Japanese culture, you cannot miss Japanese hot springs (onsens). Renowned for their therapeutic benefits and serene ambiance, onsens hold a sacred place in Japanese society, dating back centuries. Rooted in the belief of purifying both body and soul, these natural mineral geothermal baths serve as sanctuaries where visitors can unwind and connect in a beautiful natural setting. Beyond their restorative properties, onsens are the epitome of Japan’s reverence for harmony with nature and communal wellbeing, making them a must-visit for travellers hoping to immerse themselves in authentic Japanese culture. 

What is a Japanese onsen?

An onsen is a hot spring, although the term is often extended to also describe the bathing facilities, outdoor baths, spas and inns around the hot springs. For many visitors, the onsen is somewhat unfamiliar territory and the whole concept of communal public bathing may seem a little intimidating and even slightly uncomfortable as you will be sharing a bath with strangers wearing nothing but your birthday suit.

I would urge you to give it a go though – visiting an onsen is a great way to rejuvenate tired muscles after a long day of trekking and leaves you feeling refreshed and clean. I dare say it might even become an addiction!

Due to Japan being located in a volcanic zone, natural hot springs are numerous and extremely popular in Japan – for hundreds of years Japanese people have enjoyed onsens as a way of socialising and for their many health benefits and healing qualities. They are also an important part of religious traditions with pilgrims performing hot water purification rituals in preparation for visiting sacred sites.

Did you say hot spring flowers?

For the Japanese, the purity and the quality of the water is the main factor. Hot spring waters are rich in minerals and by law (!) all onsens must contain at least one of the 19 designated chemical elements such as iron or sulphur.

Due to the high mineral content, you may sometimes find small white clumps floating in an onsen. These are minerals clinging together – in Japanese, it is called “Yu-no-hana”, translating as “hot spring flowers”. They are a sign of high-quality hot spring water. The strong mineral content may also stain baths and for those not used to this phenomena, the bathwater may seem unclean. However, it is actually the opposite – it is very pure natural onsen water!

Beginner’s guide to onsen culture: rules and etiquette

Onsens are an important part of Japanese culture and daily routine. Correct manners are very important for the Japanese and it comes as no surprise that a proper onsen etiquette is well-established.

First timers can be a little intimidated with rules and etiquette, so we have compiled some tips and guidelines below to ensure you enjoy your onsen experience.

Entrance and change rooms

The entrance to an onsen is typically marked by noren curtains (traditional Japanese fabric dividers), blue for male (男) and red for female (女). Guesthouses, known as ryokan, sometimes switch onsens, meaning an onsen that was a female one yesterday may today be a male one. Remember to check the colour and/or the symbol every time when entering! Some accommodations have got limited bathing times whereas others have 24-hour options available.

Most onsens will have a change room for undressing and baskets are generally provided to leave your clothes in. Remove jewellery and other accessories such as watches and glasses as the mineral rich water can discolour these. In case it’s not clear yet, it is nude bathing we are talking about here but you will be provided with a small modesty towel which you can wear to cover up between the change room and the bath if you wish.

Washing and bathing in an onsen

Washing and bathing areas are separate and the water from both should not mix. Baths in Japan are for soaking and relaxing, not cleaning the body, so remember to wash yourself thoroughly before entering the onsen. Most bathing areas have got small stools to sit on and wash yourself away from the actual hot spring bath. If the bathing area doesn’t have showers, use the provided washing buckets – this is the truly traditional style of onsen bathing!

You can use your modesty towel to cover up while washing but make sure not to bring the towel or any type of swimwear in the bath as they are seen as dirtying the onsen and this will not be well received by your fellow Japanese bathers.

Enter the water slowly to allow your body to adjust to the water temperature – hot spring baths aren’t called hot for no reason! Now relax and enjoy.

Leaving the onsen

Once you feel like you are relaxed (hopefully not traumatised) enough, stand up slowly – there are several onsen injuries reported every year due to fainting so take your time here. Some hot springs recommend not to rinse after the bath to obtain the full effect of the hot spring minerals but you should do so if you have sensitive skin. After leaving the bath, wipe off excess water and sweat prior to re-entering the change room to keep the area dry and clean. Remember to drink lots of water after your bath to keep yourself well hydrated. Slip on a yukata and chill!

Important rules to remember when visiting onsens

• Photography is not permitted inside bathing areas.
• Swimsuits are not permitted inside onsens; they are, however, permitted in public outdoor onsens (for example, Kawayu Onsen).
• Modesty towels are not permitted inside the bath itself.
• Do not bring phones, books or newspapers into the bathing area.
• Do not put your head under water in the bath.
• In some locations, it is only possible to bathe in the evenings.
• In most onsen, tattoos are not technically allowed (the taboo stems from their association with members of Japanese organised crime). Some people choose to cover their tattoos with a waterproof bandage. Please seek advice from our Japan destination specialists if this applies to you.

While you are in the onsen:

• Leave your footwear on the shelf at the entry to the onsen.
• Remove your clothing or yukata and store it in the baskets provided.
• Remove all jewellery and watches before soaking as these can be discoloured by the mineral-rich waters.
• If you have long hair, tie it up before soaking.
• If you are feeling embarrassed, use your small modesty towel to cover yourself while entering the bathing area.
• Walk slowly – the floors are often wet and slippery.
• Wash carefully before you enter the onsen bath. This is very important. Most baths have small stools to sit on away from the bathing area. Many onsens also provide soap, shampoo and conditioner otherwise you can bring your own if you prefer.
• Enter the water slowly to allow your body to adjust to the water temperature.
• If your modesty towel accidentally falls into the bath, wring it out away from the bath.
• Drink plenty of water before and after your bath to prevent dehydration.

Popular onsen destinations

Please note these are not included in any of the RAW Travel walking tours, but are only options for any further possible travel you might want to do.

• Hakone Onsen: It’s one of the most famous onsen resorts in Japan, located in a mountain town with a wide range of onsens available. It’s easy to reach via train as a day trip from Tokyo.
• Kinosaki Onsen, located in Hyogo, is very inclusive for overseas visitors, and welcomes people with tattoos.
• Beppu Onsen is made of eight different onsen areas, and known as the onsen capital of Japan. It also includes mud, steam and sand bathing options.
• Kurokawa Onsen is one of the oldest and most beautiful onsens in Japan. Visitors have over 30 baths to choose from, and can buy a pass that includes entry to three of their choosing.

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