"Is it true that families share the same bathwater?"

Many foreigners ask this. The answer: yes, it's true. But there's a precondition: you wash your body completely before getting into the tub. This is the central principle of Japanese bathing culture.

The same idea applies whether you're at home, in a sentō, or in an onsen. The tub is not where you wash — it's where you warm your body and rest your mind.

This guide walks through how to bathe at home, in a sentō, and in an onsen — and addresses the tattoo question that almost every foreign visitor wants to know about, with the latest 2026 information.

The core principle: wash before the tub

Whether at home, a sentō, or an onsen, the flow is the same.

  1. Undress completely in the changing room (no swimsuits, no underwear)
  2. When entering the bath room, start with kake-yu (pour water over yourself with a small wooden bucket)
  3. Wash your hair and body at the washing station (use shampoo and soap)
  4. Rinse off all foam with the shower
  5. Slowly enter the tub to warm up
  6. When you're done, dry off and return to the changing room

Things you must not do: entering the tub with soap foam still on you, washing inside the tub, putting your towel in the tub, putting your hair in the water. These are major etiquette violations in public bathhouses, and they cause family disputes at home too.

Home baths

Home bathrooms in Japan typically have a separate washing station alongside the tub. Because they're physically separate, the bathwater stays clean.

"Oidaki" — reheating

"Oidaki" is the function that reheats the bathwater. The whole family takes turns in the same water, reheating it as it cools. This is economical and reflects a long-standing tradition of not wasting hot water.

Order of bathing

Traditionally:

  1. The head of the household (father)
  2. Children
  3. Mother

Modern households are flexible, but the awareness of "keeping the bathwater clean" still persists.

How to use a bath ideally

  • Daily: Most Japanese people soak in the tub every day (rather than just showering)
  • Time: 10–20 minutes, slowly
  • Temperature: 38–41°C is ideal
  • Effects: improved circulation, muscle recovery, better sleep, stress relief

Sentō — the neighborhood community bath

A "sentō" is a public bathhouse with roots going back to the Edo period. Originally for people without baths at home, today they're places people visit to relax in a large bath.

Prices

Each prefecture sets a price ceiling under the Price Control Ordinance.

Region Adult fee (2026)
Tokyo ¥550
Osaka ¥520
Kyoto ¥510
Aichi ¥490
Most other prefectures ¥450–520

Children under 6 pay around ¥100 in many areas; elementary-age children pay roughly half adult price.

What to bring

  • Towels (a small one for washing + a larger one for drying after)
  • Shampoo and soap (many sentō have these on-site)
  • Clean underwear
  • Coins (for the locker and vending machines)

The flow

  1. Pay at the entrance counter (bandai) or ticket machine
  2. Identify the men's vs. women's bath: doorway curtains (noren) are color-coded — men's typically blue or navy, women's typically red or pink
  3. Use a locker in the changing room (most are 100-yen return-deposit type)
  4. Bathe following the core principle above
  5. Dry off in the changing room and dress
  6. Drink milk or coffee-flavored milk in the rest area (a beloved sentō tradition)

Sentō-specific facilities

  • Jet baths
  • Electric bath (mild current for muscle relaxation)
  • Sauna
  • Cold-water bath (after the sauna)
  • Yakuyu (medicinal herb-infused water)

Onsen — bathing for tourism and health

An "onsen" is a bathing facility using natural hot water from underground. Under the Hot Springs Act, the water must meet criteria for dissolved minerals and temperature (25°C or above).

Types of onsen

  • Simple springs (tanjun onsen): Colorless, odorless, gentle on skin
  • Sulfur springs (iō-sen): Cloudy white, distinct sulfur smell, good for skin conditions
  • Bicarbonate springs: Known as "beautifying baths" — leaves skin smooth
  • Chloride springs: Strong heat retention, helps with cold sensitivity
  • Radium springs: Trace radon, said to balance the autonomic nervous system

How to enjoy onsen

Day-trip onsen

Urban and suburban "super-sentō" and day-trip onsen facilities (¥800–1,500). Big tubs, saunas, dining areas, massage, and even manga corners — easy to spend half a day.

Onsen ryokan

Rooted in the tradition of "tōji" — extended onsen stays for healing. Stay overnight with two meals (¥10,000–50,000 per person per night). Change into yukata, hop between baths, and enjoy kaiseki cuisine.

Open-air baths (rotenburo)

Outdoor baths. A luxurious experience — bathing in nature with snow scenery, autumn leaves, or a starry sky.

Famous onsen destinations

Region Name Notable feature
Gunma Kusatsu Onsen Strongly acidic water, traditional yumomi performance
Oita Beppu / Yufuin "Hells of Beppu" tour; highest output volume in Japan
Gifu Gero Onsen One of Japan's three top hot springs
Hyogo Arima Onsen Gold and silver springs
Tochigi Kinugawa / Nikko Yumoto Easy from greater Tokyo
Kanagawa Hakone Day trip from Tokyo possible

The tattoo question

This is the single biggest worry for foreign visitors.

Historical background

Historically, tattoos in Japan were associated with organized crime (yakuza), and many sentō and onsen refused entry to anyone with visible tattoos.

A 2015 Japan Tourism Agency survey found that of onsen facilities surveyed, about 56% refused, about 31% allowed, and about 13% allowed conditionally with cover-up.

Recent changes

Since 2020, the rapid increase in foreign visitors and the rise of fashion tattoos among young Japanese have driven major liberalization. In 2024, the Japan Tourism Agency issued guidelines encouraging facilities to:

  • Provide free cover stickers
  • Display multilingual signage
  • Offer private bath options
  • Accept tattoos under 10cm

How to find tattoo-friendly facilities

1. "Tattoo Friendly" sites and apps

Tattoo Friendly and Tattoo GO let you search for tattoo-friendly sentō and onsen.

2. Nifty Onsen's tattoo-OK feature

Nifty Onsen lets you search "tattoo-OK" facilities by prefecture.

3. Bring cover stickers

  • Buy "tattoo cover stickers" at drugstores or on Amazon (¥1,000–2,000 for a 10-pack)
  • Standard size is roughly 10cm × 14cm
  • Waterproof, designed not to peel off in water

4. Private baths or rooms with private baths

Onsen ryokan offer private family baths (kashikiri-buro) or rooms with attached open-air baths — perfect for enjoying without worrying about tattoos (extra fee around ¥2,000–5,000).

5. Old-town and rural sentō are often surprisingly relaxed

Long-established neighborhood sentō have lots of older male regulars and are used to tattooed customers. They tend to be more accepting than larger facilities.

Etiquette summary

Things you must not do

  • Wash your body inside the tub
  • Enter the tub without rinsing off foam
  • Put your towel in the water
  • Put your hair in the water (tie up long hair)
  • Talk loudly
  • Take photos (strictly forbidden in changing rooms and bath areas)
  • Bring your smartphone past the changing room
  • Bathe after drinking alcohol (sudden blood pressure changes, drowning risk)
  • Leave small children to bathe alone

Recommended actions

  • Dry off thoroughly in the changing room (don't drip water on the floor)
  • Return your basin and stool to their original spot, and rinse them with the shower for the next person
  • Hydrate after bathing (to prevent dehydration)

FAQ

Q. Are there onsen where I can wear a swimsuit?

A. Very few — some mixed-gender open-air baths allow bathing wear, and some onsen with attached pools allow swimsuits. As a rule, swimsuits are not allowed. Bathing nude is considered more hygienic (no fibers from clothing entering the water).

Q. Can I bathe with my child?

A. Many facilities allow pre-school children to enter the opposite-gender bath with a parent. However, age limits have tightened in recent years — most facilities now require children aged 7 and older to use the same-gender bath (or a private family bath).

Q. Can I bathe during my period?

A. Generally, custom is to abstain (most facilities post a notice). Modern hygiene debates aside, please factor in consideration for other bathers.

Q. What about glasses and contact lenses?

A. Both are generally fine. However, glasses can get dangerously hot in saunas or very hot baths. Contacts may dislodge if water enters your eyes — be careful.

Q. Is it OK to soak in onsen for a long time?

A. The ideal is about 10 minutes per session, getting in and out repeatedly. Long soaks cause dizziness, dehydration, or "yu-atari" (literally "bath shock"). Sulfur and acidic springs are especially intense — sometimes you should rinse with plain water after a long soak.

Q. Are the medicinal effects of onsen real?

A. The medically established benefits are mainly improved circulation and muscle relaxation from heat. Specific disease-curing claims are limited. People with chronic conditions should consult their doctor before use.

Q. What do I do with my wallet and valuables at the sentō?

A. Lock them in a changing-room locker (most are 100-yen return-deposit type). Best practice: don't bring large amounts of cash or valuables.

Q. Where do I buy tattoo cover stickers?

A. Major drugstore chains (Matsumoto Kiyoshi, Welcia, etc.) and Amazon / Rakuten — search for "tattoo cover sticker" or "large bandage tape." More onsen facility shops also carry them now.

Final thoughts

Japanese bathing culture has a long history as a place to "purify the body" and "rest the mind." Things to do today:

  1. Make "wash before the tub" a habit
  2. Visit one local sentō (cheap, spacious, a real cultural experience)
  3. If you have tattoos, look up tattoo-friendly facilities on Tattoo Friendly in advance
  4. On onsen trips, prevent yu-atari by soaking briefly multiple times rather than once for long

The moment you sink your bare body into hot water, your head and body relax together — many foreigners say this is one of the moments they most appreciate Japan.

At Nihongo-tomo, we offer free vocabulary lists for sentō, onsen, and bathing supplies. Learning words like "yubune" (bathtub), "kake-yu" (initial water rinse), and "rotenburo" (open-air bath) ahead of time makes your first onsen trip far more enjoyable.

References / 参考・出典

All content in this article is based on general etiquette and pricing as of May 2026. Tattoo policies vary by facility — confirm with each facility before visiting.