Onsen (hot springs) are one of the most important cultural experiences in Japan. There are over 27,000 hot spring sources across the country, and bathing in them has been a part of Japanese life for centuries.
For many foreign visitors, the idea of bathing nude with strangers is intimidating. This guide will make it simple.
The Basic Rules
Before You Enter the Bath
- Remove all clothing in the changing room (脱衣所). Put your clothes in a basket or locker
- Take the small towel provided. This is your washing towel — never put it in the bath water
- Wash your body thoroughly at the shower stations before entering the bath. Sit on the stool, use the soap and shampoo provided, and rinse completely
- Tie long hair up so it does not touch the water
In the Bath
- Enter slowly. The water is typically 40-44°C (104-111°F). Your body needs time to adjust
- Do not put your towel in the water. Fold it and place it on your head — this is the classic onsen pose
- Do not swim or splash. Onsen are for soaking quietly
- Do not stare at other bathers. Everyone is politely ignoring each other’s nudity
- Soak for 10-20 minutes. Longer sessions can cause dizziness from the heat
After the Bath
- Do not rinse off the mineral water — the minerals continue working on your skin
- Dry off before returning to the changing room so you do not wet the floor
- Drink water or milk. Most onsen sell cold milk in glass bottles. This is tradition
Tattoo Policies
Japan has a complex relationship with tattoos due to their association with yakuza (organized crime). Many onsen and sento (public baths) prohibit tattooed visitors.
The reality in 2026:
- Large resort onsen — Many are relaxing their tattoo policies, especially in tourist areas. Some provide skin-colored cover patches
- Small local onsen — More likely to prohibit tattoos, but also less likely to confront you
- Private onsen (kashikiri/family bath) — Available at most ryokan. You rent the entire bath for your group. No restrictions. This is the guaranteed solution
- Outdoor baths (rotenburo) — Some rural outdoor baths are more relaxed about tattoos
Tip: Before visiting, call ahead or check the onsen’s website for their tattoo policy. The Japanese phrase is “irezumi wa daijoubu desu ka?” (入れ墨は大丈夫ですか？)
Types of Onsen
Gender-Separated Baths (男女別)
The most common type. Men and women bathe in separate areas. Look for the kanji:
- 男 (otoko) = Men
- 女 (onna) = Women
- The curtain color also helps: blue for men, red/pink for women (usually)
Mixed Baths (混浴 — konyoku)
Increasingly rare, but they exist in rural areas. Both genders bathe together. In practice, you will find mostly older Japanese people. Some mixed baths allow women to wear towels.
Private/Family Baths (貸切風呂)
Rent an entire bath for yourself, your partner, or your family. Typically 45-60 minutes for ¥2,000-5,000. Perfect for:
- Couples
- Families with children
- Anyone uncomfortable with public nudity
- Tattooed visitors
Rotenburo (露天風呂 — Outdoor Baths)
Open-air baths with views of mountains, rivers, or the ocean. These are the most memorable onsen experiences. Many ryokan have private rotenburo attached to the room.
What the Water Does
Different onsen have different mineral compositions with different effects:
| Water Type | Color/Feel | Good For |
|---|---|---|
| Sulfur (硫黄泉) | Milky white, egg smell | Skin conditions, circulation |
| Iron (鉄泉) | Reddish-brown | Anemia, menstrual issues |
| Salt (塩化物泉) | Clear, salty taste | Warming the body, joint pain |
| Carbon dioxide (炭酸泉) | Tiny bubbles on skin | Blood pressure, circulation |
| Alkaline (アルカリ泉) | Silky, smooth feeling | Softening skin (“beauty bath”) |
Recommended Onsen Areas
Near Tokyo
- Hakone — Multiple onsen types, mountain views, accessible by Romancecar from Shinjuku (85 minutes)
- Kusatsu — One of Japan’s top three onsen. Famous for the yubatake (hot water field) in the center of town
- Kinugawa — River gorge setting, perfect combined with Nikko
Further Afield
- Ginzan Onsen (Yamagata) — Snow-covered ryokan street, the most photogenic onsen town
- Noboribetsu (Hokkaido) — Hell Valley with multiple water types
- Beppu (Oita) — The onsen capital of Japan with the most variety
Sento vs. Onsen
| Sento (銭湯) | Onsen (温泉) | |
|---|---|---|
| Water | Heated tap water | Natural hot spring |
| Location | Cities, neighborhoods | Mountain towns, resort areas |
| Price | ¥500-800 | ¥800-2,000+ |
| Bring | Own soap/towel (or buy) | Usually provided |
| Experience | Local, everyday | Special, travel-worthy |
Both follow the same etiquette rules.
Your First Time — Step by Step
- Pay at the front desk
- Take off shoes at the entrance (use shoe locker)
- Go to the correct gender side
- Undress completely in the changing room
- Take small towel to washing area
- Sit on stool, wash entire body with soap
- Rinse thoroughly
- Walk to the bath, enter slowly
- Soak quietly for 10-20 minutes
- Get out, towel on head, cool down
- Repeat if desired
- Return to changing room, dry off
- Get dressed, drink cold milk, feel reborn
The first time is awkward. The second time is comfortable. By the third time, you will understand why Japan has been doing this for a thousand years.