How to Use Japanese Onsen and Sento: Etiquette, Tattoos, and Towel Rules

If you’re traveling in Japan, you may want to try an onsen or sento.

But if it’s your first time, you may be wondering:

“Do I wear a swimsuit?”
“When do I wash?”
“Can I put my towel in the bath?”
“What if I have a tattoo?”

It can be surprisingly confusing the first time.

Here are the five basics to remember first.

What’s the Difference Between an Onsen and a Sento?

It may seem simple to think of an onsen as “natural hot spring water” and a sento as “regular bathwater,” but the real difference is a little more precise.

Put simply, onsen is mainly about the water, while sento is about the type of bathing facility.

Under Japan’s Hot Spring Act, hot water, mineral water, and similar substances that emerge from underground qualify as onsen if the source temperature is at least 25°C, or if they contain certain substances in amounts specified by law.

Japan’s Ministry of Health, Labour and Welfare defines a public bath as a facility that allows the public to bathe using hot water, seawater, hot spring water, or other types of water. A sento is a type of public bath commonly used by local residents in daily life.

So, some sento actually use natural hot spring water.

If you specifically want to bathe in natural hot spring water, check the facility’s official website rather than relying on the name alone.

Can You Use an Onsen Without Staying Overnight?

Yes.

Many onsen facilities can be used without staying overnight.

In Japan, this is often called:

Some ryokan also allow non-guests to use their baths during designated hours.

However, not every ryokan or onsen offers day-use bathing.

Once you know where you want to go, check the official website for:

A sento is a public bath meant for people to come in and bathe, so you do not need to be staying anywhere to use one.

What Should You Bring to an Onsen or Sento?

At hotel and ryokan baths, towels, shampoo, body soap, and similar items are often provided.

At a neighborhood sento, it’s safer to assume you may need to bring your own towels and toiletries.

According to Tokyo Sento’s official guidance, many sento sell towels, shampoo, soap, disposable razors, and other basic items. Some also provide shampoo and body soap for free.

Facilities differ, though.

If it’s your first visit to a sento, these are useful things to bring:

If you want to keep your luggage light, check the facility’s official website for towel sales or rentals and whether shampoo and body soap are provided.

How to Use a Japanese Onsen or Sento

Here’s what to do once you arrive.

1. Take Off Your Shoes and Pay at Reception

At many sento, you take off your shoes at the entrance and place them in a shoe locker, then pay at the front desk or a ticket machine.

At a hotel or ryokan, use of the public bath may already be included in your stay.

The exact entrance and payment process varies, so follow the signs and instructions at the facility.

2. Check Which Entrance Is for Men and Which Is for Women

Most onsen and sento have separate bathing areas for men and women.

You may see these Japanese characters:

Some facilities use blue entrance curtains for the men’s bath and red ones for the women’s bath, but don’t rely on color alone—check the 男 and 女 signs as well.

At some ryokan and hotels, the men’s and women’s baths switch at different times of day.

Don’t assume the entrance is the same just because you used it the day before.

Check the Age Rule if You’re Bathing With a Child

If a child is going into a bath with a parent or guardian of a different sex, age limits apply.

As a nationwide guideline, Japan’s Ministry of Health, Labour and Welfare says that boys and girls “approximately 7 years old and above” should not bathe together.

As a general guideline, children age 6 and under may bathe with a parent or guardian of a different sex.

However, local regulations or individual facility rules may set a lower age limit.

If you’re bathing with a child, check the age rule at the facility you plan to visit.

3. Undress Completely in the Changing Room

At a typical Japanese onsen or sento, you bathe completely nude, without a swimsuit or underwear.

Leave your clothes and underwear in a basket or locker in the changing room.

Take the towel you plan to use in the bathing area, along with anything else you need, such as a razor, shampoo, or body soap.

If you feel shy walking around nude, some people lightly cover themselves in front with a towel while moving through the bathing area.

But that towel should not go into the bathwater.

4. Wash Before Getting Into the Bath

At Japanese onsen and sento, the bathwater is shared by many people.

Guidance for travelers from the Japan National Tourism Organization (JNTO) and the Japan Tourism Agency advises visitors to wash at the washing area, rinse off all soap and shampoo, and then enter the bath.

Tokyo Sento’s official guidance describes another sequence: rinse yourself with kakeyu first, warm up in the bath, and then wash your body.

So the recommended order differs slightly between guides.

If it’s your first time, washing your body thoroughly before getting into the bath is the simplest approach.

The bathing area usually has low stools, wash bowls, and showers.

If you’re wearing makeup, remove it before getting into the bath.

There is also a Japanese bathing custom called kakeyu (かけ湯), where you pour warm water over your body before entering the bath.

This also helps your body adjust to the water temperature before you step into the hot bath.

5. Keep Your Towel and Hair Out of the Bathwater

Once you’re clean, it’s time to get into the bath.

The important rule here is: don’t put your towel in the bathwater.

The towel you take into the bathing area can be used to:

When you get into the bath, you can:

If you have long hair, tie it up or otherwise keep it from touching the bathwater.

Some people use a towel to keep their hair up, but the towel itself still should not go into the water.

That’s why you may see people sitting in the bath with a towel on top of their head.

If you have a larger bath towel, you can usually leave it in the changing room.

If you have short hair, you can often manage with just one towel in the bathing area: use it to wash, wring it out, then use it to wipe off some water before you leave.

The bath is also not a place for swimming or splashing around. Relax and soak quietly.

6. Wipe Off Before Returning to the Changing Room

When you’re finished bathing, head back to the changing room.

Before you do, use the towel you brought into the bathing area to wipe off some of the water on your body.

This helps keep the changing-room floor from getting wet.

If you brought a bath towel, use it in the changing room to dry yourself properly before getting dressed.

Whether you should rinse off again with a shower after soaking in an onsen is not a universal rule. If the facility gives specific instructions, follow them.

7. Rehydrate After Bathing

Onsen and sento can warm you up more than you expect.

Don’t force yourself to stay in the bath for too long. If you start feeling too hot, get out and take a break.

It’s also a good idea to drink fluids before and after bathing.

If the facility has a drink vending machine, you can use it to rehydrate afterward.

Can You Use an Onsen or Sento if You Have a Tattoo?

Tattoo rules vary by facility.

Some facilities allow guests with tattoos, while others do not.

You may also find rules such as:

The Japan Tourism Agency explains that some bathing facilities in Japan have historically refused entry to people with tattoos because tattoos have been associated with anti-social groups. At the same time, it notes that some ryokan now place no restrictions on foreign travelers with tattoos, while others decide case by case.

JNTO also explains that tattoo policies vary by facility and that some local sento accept people with tattoos.

So, if you have a tattoo, the most reliable approach is to check the facility’s official rules before you go.

Can You Cover a Small Tattoo?

If a facility says tattoos up to a certain size are allowed when covered, you can use the bath as long as you follow that rule.

However, covering a tattoo does not mean you can use every onsen.

Some facilities do not allow tattoo covers at all.

Don’t assume a small tattoo will be fine. Check the facility’s own rules.

If You Have a Large Tattoo, a Private Bath May Be an Option

If your tattoo is too large to cover, or you prefer to avoid a crowded shared bath, you can:

However, a private bath is not automatically tattoo-friendly everywhere in Japan. Check the rules at the facility you plan to use.

What if You’re Uncomfortable Bathing Nude?

At a typical Japanese onsen or sento, you cannot wear a swimsuit in the shared bath.

If you’re uncomfortable being nude around strangers, you do not have to force yourself to use a public bath.

Choose a private bath or a guest room with its own bath.

With a private bath, you can bathe without sharing the space with other guests.

It can also be a convenient option for families or couples who want to bathe together.

However, having a private bath in your room does not automatically mean the water is from a natural hot spring.

If the hot spring water itself matters to you, check the accommodation’s official website to see whether the private bath uses onsen water.

Keep Smartphones and Cameras Out of the Bathing Area

This is important.

Other people are nude in onsen and sento bathing areas.

JNTO also advises visitors not to use smartphones or cameras for photography in onsen bathing areas out of respect for other guests’ privacy.

Even if it looks like no one else is there, don’t think, “I’ll just take one quick photo.”

Some facilities also prohibit smartphone use in the changing room itself.

It’s best to keep your phone put away in your locker or bag in both the bathing area and the changing room.

Hot Spring Towns Offer More Than Bathing: Onsen Eggs and Jigoku Mushi

In some Japanese hot spring towns, you can also enjoy food prepared using heat from the hot springs.

One well-known example is the onsen egg.

In some hot spring areas, eggs are cooked using the heat from the hot springs and sold on the spot.

Another interesting example is jigoku mushi in Beppu, Oita Prefecture.

Jigoku mushi is a cooking method that uses high-temperature steam rising from the hot springs to steam vegetables, meat, seafood, and other foods.

In Beppu’s Kannawa Onsen area, this traditional cooking method has been used since the Edo period, and today there are facilities where travelers can try jigoku mushi for themselves.

Which Type Should You Choose for Your First Visit?

It depends on what you want from the experience.

For a first visit, I recommend choosing a facility whose official website clearly explains how to bathe and what its tattoo rules are.

That way, you’re less likely to arrive and wonder, “Am I actually allowed to do this?”

Before You Use a Japanese Onsen or Sento, Check These Basics

Here’s the order I recommend checking things in.

Japanese onsen and sento have their own rules, but they’re not there to make bathing complicated.

They’re there so everyone can share the same bath comfortably.

Once you know the basics, you’ll be fine.

If you’re visiting Japan, choose the bathing style that suits you and enjoy the experience.