Guide · Akihabara

Onsen and Sento Etiquette: The Rules, Step by Step, from a Tokyo Guide Who Uses Them

You bathe naked, you wash and rinse completely at the seated shower stations before you enter the bath, and the bath itself is only for soaking — no soap, no swimsuit, no towel in the water. Baths are separated by gender. Tattoo policies vary by facility, so if you have visible ink, check before you travel rather than at the door.

Once you understand that the bath water is shared and never drained between guests, every rule here writes itself. You do not wash in it. You arrive at it already clean.

What's the difference between an onsen and a sento?

An onsen uses naturally occurring hot spring water and is often a destination in itself. A sento is a public bathhouse heated with ordinary water, historically a neighbourhood facility for people whose homes had no bath. The etiquette is essentially identical in both.

Practically: a sento is cheap, local and often has a wonderfully unchanged mid-century interior. An onsen may be a day facility, part of a hotel, or an inn where the bath is the reason you came. A rotenburo is an outdoor bath, which is the one worth planning a trip around in winter.

The sequence, in order

Shoes off at the entrance, pay, take your towels, undress completely in the changing room, wash sitting down at a shower station, rinse every trace of soap, then soak. Reverse it on the way out: wring out your small towel, dry off before you step back into the changing room, dress, drink water.

1. Shoes off at the door and into a locker or shelf. See where you take your shoes off.
2. Pay at the counter or a machine. Small towel and large towel are often rented separately. Buy the soap set if you did not bring one.
3. Find your gender's curtain. Red or pink is usually women, blue or dark is usually men, and the kanji are 女 (women) and 男 (men). They sometimes swap between days at facilities that rotate their baths, so read the sign each time.
4. Undress fully in the changing room. Everything goes in the basket or locker, including underwear. There is no partial version of this.
5. Take only the small towel through to the bath.
6. Wash sitting down at a shower station: stool, bucket, shower head, soap and shampoo usually provided. Wash thoroughly, hair included, and rinse until no foam remains anywhere.
7. Rinse your station for the next person and leave the stool and bucket as you found them.
8. Enter the bath slowly. No jumping, no swimming, no splashing.
9. Keep the small towel out of the water. Fold it on your head — the classic image is a genuine practice — or leave it at the edge.
10. Dry off with the small towel before you walk back into the changing room, so you do not soak the floor.

The rules people break by accident

The common visitor mistakes are entering the bath without washing properly, putting a towel or hair in the water, taking a phone into the bath area, and talking loudly. The first is the one that genuinely matters to everyone else in the water.

• Long hair goes up. Tie it so it does not touch the water.
• No phones or cameras. At all. This is a room full of naked strangers, and it is the one rule where a mistake is a serious incident rather than a faux pas. Leave the phone in the locker.
• No swimsuits in a traditional bath. If a facility permits them it is a bathing complex or a water park, not an onsen, and it will say so.
• Voices down. People are here to be quiet.
• Do not stare, and do not use the small towel as an elaborate shield either. Everybody is naked and nobody is looking. Confidence is more polite than obvious embarrassment.
• Drinking and bathing do not mix, and many facilities post exactly that.
• Hydrate afterwards. The milk fridge in the changing room is a tradition and a good idea.

Can I go to an onsen with tattoos?

It depends entirely on the facility. Many traditional onsen and sento still prohibit visible tattoos, because of a long-standing association with organised crime; many others now admit tattooed guests, particularly in tourist areas and at newer facilities. There is no national law involved — it is each operator's house rule, so the only reliable answer is the one you get from that specific bath.

If you have tattoos, you have four workable routes:

1. Check the facility's own page before you go. Many now state their tattoo policy explicitly in English, and there are tattoo-friendly onsen directories maintained for visitors.
2. Cover small tattoos with waterproof cover stickers, sold in Japan and online. Some facilities accept this explicitly, some do not; a tattoo the size of a postcard is a different conversation to a full sleeve.
3. Book a private bath. Kashikiri-buro (reserved bath) and family baths are private rooms, usually bookable by the hour, and generally sidestep the question entirely.
4. Book a room with its own bath. Many inns have rooms with a private open-air bath. It costs more and removes the problem completely.

I would rather you plan around this than arrive and be turned away at the counter, which is an unpleasant experience for everyone involved including the staff member who has to say it.

Frequently asked questions

Can men and women bathe together? Almost all baths are separated by gender. Mixed-gender baths (konyoku) still exist in a small number of mostly rural places, often with rules about wearing a bathing garment, and they are the exception rather than something you will encounter by accident.

What if I have my period? The standard advice is to skip the shared bath, since the water is shared and undrained. A private bath or a hotel room bath is the alternative.

Are children allowed? Yes, and family bathing is completely normal. Younger children usually go with a parent of either gender, with facilities setting their own age limits for which side a child may enter.

Is it OK if I don't know what I'm doing? Yes. Watch, go slowly, and wash more thoroughly than you think you need to. Regulars are generally kind about visitors making an obvious effort, and the one thing that draws a comment is entering the bath unwashed.

Do I need to bring anything? A small towel and a large towel, and soap if it is a basic sento. Most facilities rent or sell all three. Take a coin for the locker at older places.

Can I take my glasses in? Yes, glasses are fine. Contact lenses are usually best removed before the bath.

Learn the basics before you need them

An onsen is not usually day one, but the habits behind it — shoes off, look for the system, be quiet in a shared space — are exactly what day one teaches. Tokyo First Day Tour: Japanese Manners & Survival Class is a three-hour walking lesson on your first or second morning in Japan, and by the time you reach a bathhouse later in your trip, the instincts are already built.

The full map: Japanese etiquette: a complete guide for first-time visitors.

About the author. I am Yuuki, a Japanese teacher and Akihabara tour guide in Tokyo. I run small-group tours in English most weeks, rated 4.96★ on Airbnb, and I have watched over 1,500 anime series — which is how most of my guests find me. The fold-the-towel-on-your-head thing is not a joke.

See the Akihabara anime tour →

Sources: Ministry of Health, Labour and Welfare, Public Bathhouses (公衆浴場のページ), which carries the 2016 government guidance on bathing for foreign visitors with tattoos; Japan National Tourism Organization, Japanese Onsen and Ink — The Tattoo Taboo.