In Japan, clothing, towels, and any other garments are considered sullied or “dirty” and should never, ever be brought into an onsen. Nudity is expressly required, but really, it's no big deal. If you've ever had to shower in gym class (who hasn't?), nudity in an onsen is much less embarrassing.
Onsen Etiquette Before Entering the Onsen
When entering a hot spring, please take off all clothing, including underwear. It is against Japanese custom to enter the water whilst wearing any items of clothing.
First, what do you wear in an onsen? With a few exceptions (like Kitahama TERMAS and Kaihin Sunayu) you will be completely nude while bathing and separated by gender, so there is no need to worry too much about your outfit. Perhaps easily removable clothing is preferable.
This social aspect, however, led many onsen and sento to prohibit tattooed guests. The Japanese taboo toward tattoos stems from their association with members of Japanese organized crime. Gangsters in Japan are typically heavily tattooed, and body art in Japan came to be associated with unsavory characters.
The Japanese have perfected the art of onsen, or hot spring baths, for centuries. Traditionally, men and women would bathe together in the same facility, but these days the baths are segregated by gender. Today, konyoku (mixed-gender onsen) are hard to find, with places like Tokyo having bans on such establishments.
Avoid bathing in an onsen in the following cases. If you have chronic bronchitis and fever or difficulty in breathing. If you have stable angina and chest pain becomes frequent. Bathing may cause serious problems with dehydration or thrombosis.
Most onsen today are segregated by gender, meaning couples cannot bathe together. However, Japanese private onsen offers you and your loved one a highly luxurious and romantic bathing experience, often complete with spectacular views.
Onsen Etiquette
If you have any tattoos or body piercings, it is possible that you won't be allowed to enter. Be sure to remove any piercings (ears are okay) and conceal any ink.
Although swimsuits are allowed in a select few onsen, this is very rare. In most onsen, you take off all your clothes in the dressing room. Clothing and garments that are worn outside are considered sullied and should never be brought into an onsen. Nudity is a must for taking an onsen.
Some tips and tricks for visiting onsen if you have tattoos
Friends of mine with smaller tattoos have gotten away with covering them with bandages or even using their small onsen towel to obscure them. For those with back tattoos, leaning against the wall while in the water has worked.
For those opting for tampons, make sure that the string is not clearly visible and change it as soon as you leave the onsen. Wash yourself well and refrain from using another tampon right away — give yourself enough time to cool down first.
In general, it is acceptable for men to shave in the shower area of the onsen, and razors are even provided. For women, it is not generally acceptable to shave in the onsen as this is seen as an activity that should be done privately. Japan is still a bit behind the times in gender equality.
Wash Before Entering the Onsen, Don't Wash in the Onsen
It's customary, polite and hygienic to wash your hair and body before entering the onsen water. This keeps it clean for everyone. Nobody wants to sit in someone else's dirty bathwater.
submerge your face or head, it is considered unclean. yell or speak loudly, onsen are for relaxing. run, the stone floors are usually slippery when wet. swim or splash around in the bath, no matter how tempting.
It's good manners to avoid using onsens during menstruation, particularly on heavy flow days, even when using a tampon. Onsens, like pools in Japan, do not use powerful disinfectants, so it's not very sanitary for anyone involved.
After bathing:
It is recommended that you do not shower after bathing in an onsen, as rinsing your body will weaken the minerals' healing effects.
First, there is no onsen age-limit. However, in regards to newborns, the hygienic aspect of the public bath house remains a concern. For that reason, it's better to wait a month to two months before their debut. Second, the hot spring's components make the floors slippery, so tread carefully!
Take breaks when you need to by resting on the edge out of the heat of the water and if the onsen is especially hot, don't push yourself. Many people report feeling dizzy or nauseous after their first few times after going to an onsen, and this is usually because of dehydration or overheating from staying in too long.
Onsen time varies from person to person– some people can spend up to an hour soaking in the hot water, others feel that a quick 10-minute dip is more than enough. Don't feel under pressure to stay in the onsen too long, or you could do yourself more harm than good.
Traditionally, visitors with tattoos aren't allowed in Japan's onsen (natural hot springs) because of an age-old association with organized crime. However, times are changing, and more and more onsen have relaxed their policies—in some cases to accommodate tattooed foreign tourists.
You can feel nausea after the long bathing such as discomfortness, insomnia, digestive symptoms, or dermatitis for 3 days or a week after Onsen. When you feel such, it is necessary to stop bathing or to decrease the frequency, and take rest for recovery.
Mixed-Gender, Coed, or the Konyoku is a term described to onsens that do not separate men and women. A little new and a bit uncomfortable to beginner hot spring enthusiasts, but the practice of men and women bathing together was no big deal in the early times. Konyoku, though not common, still exists in Japan.
Some onsen have a strong sulfuric smell while others have a weaker one but, in general, the milkier the water, the stronger the sulfuric smell.
But there's one particular rule around bathing in an onsen that may forbid many tourists: people with tattoos are not allowed in.
Massage with Onsen
It is essential that the hot springs are kept clean, so all guests need to shower thoroughly before entering. Since many massages involve oils, it is best to get your massage treatment later so that none of the massage oils will get in the onsen.