In Japan, onsen (温泉) are natural hot springs highly valued by both locals and foreign visitors. These baths differ from sentō (銭湯), which are public baths with artificially heated water.
Onsen are particularly cherished for their mineral-rich waters, offering various health and wellness benefits, such as muscle relaxation and mental calm.
To be classified as an onsen, the water must emerge from the ground at a temperature of at least 25°C and contain specific minerals as listed by Japanese law, making it a recognized quality label in Japan.
Why are onsen so popular in Japan?
Onsen have been deeply embedded in Japanese culture for centuries. Shinto texts mention them as early as the 700s. Initially frequented by the nobility and samurai during the Heian period (794-1185) for their therapeutic properties, their popularity spread to all social classes during the Edo period (1603-1868).
Interestingly, until Japan opened to the rest of the world during the Meiji era (1868-1912), onsen were mixed-gender, with everyone bathing nude. After the arrival of Westerners, people continued to bathe nude, but men and women were separated.
Today, onsen are social relaxation spots where Japanese people enjoy spending time with family, friends, or colleagues.
When is the best time to visit an onsen?
Onsen are accessible almost around the clock, allowing visitors to choose the time that suits them best. However, many Japanese prefer to visit in the evening to enjoy the relaxing effects before bed, which helps promote restful sleep.
How to Take a Bath in an Onsen?
Whether you're at a hotel or a dedicated onsen facility, the rules are always the same.
1) Preparation
If you're staying at a hotel or a ryokan (traditional inn), you'll find a yukata (summer kimono) and slippers in your room. Before heading to the baths, wear your yukata over your underwear, put on your slippers, and bring a large towel for drying off after the bath. You'll also find a small towel to cover your private parts when outside the bath.
Don’t be embarrassed to walk through the hallways in your yukata; it’s perfectly normal in Japan.
In onsen located outside hotels, towels are usually available for rent if you don't have your own.
No matter the type of facility, soap and shampoo are provided for free.
2) At the Entrance
You'll need to remove your shoes and place them in a locker.
If you’re coming from outside the building, plastic bags are provided to avoid dirtying the locker.
3) Changing Room
You'll easily find the women’s area, marked by a red curtain and the kanji "女" (onna/woman), while the men’s area is indicated by a blue curtain and the kanji "男" (otoko/man).
Once inside, undress completely and place your clothes in a basket or locker. Leave your large towel behind as well. If you have one, bring the small towel with you.
4) Shower
Before entering the hot water, it's essential to wash your entire body to keep the onsen water as clean as possible.
You’ll find Japanese-style showers with small seats to sit on. Use shampoo and soap to wash your entire body, including your private parts.
Once you're clean, you can enter the hot baths!
5) Relaxation in the Bath
Keep in mind that the water is maintained between 37°C and 45°C (98.6°F - 113°F), which can be surprising for beginners.
For a first experience, we recommend staying in the water for less than 5 minutes to avoid dizziness, then taking a lukewarm shower before returning to the bath. Most people don’t stay in the hot water for more than 15 minutes.
If you brought the small towel with you, don't let it soak in the water. Place it on the edge of the bath or on a wall.
6) Upon Leaving
After enjoying the onsen, take one last shower. Use the large towel to dry off, get dressed, and retrieve your shoes before leaving.
Japanese people often enjoy a milk coffee after leaving the onsen. It's somewhat akin to having popcorn at the movies.
What are the rules in onsen?
Several rules and prohibitions are in place at onsen to ensure everyone has a pleasant experience.
Tattoos
Most onsen refuse entry to people with tattoos, even small ones. It's important to check the establishment's policy before going.
This aversion to tattoos stems from two reasons:
- From 1872 until the end of World War II, tattoos were banned in Japan. This measure aimed to improve the Japanese image in the eyes of Westerners after the country opened up.
- In the 1970s, tattoos became popular among the yakuza, the Japanese mafia, giving tattoos a bad reputation.
For very small tattoos, covering them with a bandage might be sufficient. A quick online search can help you find places that accept tattooed visitors.
Towels in the Water
It’s forbidden to let your towel soak in the bathwater.
Large towels should be left with your clothes. The small towel can be kept with you but should remain on the edge of the bath while you relax.
Taking Photos
It goes without saying, but taking photos is prohibited in all onsen.
Smoking, Eating, and Drinking
Onsen are places of relaxation and purification, so smoking, eating, or consuming alcohol in the baths is not allowed.
Talking loudly, swimming, splashing…
To maintain a calm and soothing atmosphere, it’s important that all onsen visitors stay quiet and move slowly in the bathwater.
These places are not swimming pools, so activities like talking loudly, swimming, or splashing are inappropriate. Children should also behave calmly.