A visit to an onsen (hot spring) can provide one of Japan's most relaxing experiences. There are over 3,000 onsen located mostly in spa towns all over the country and while most are open year-round, the colder seasons tend to be the most popular. There's certainly nothing like dashing through the winter cold, sinking into a steaming rotenburo (outdoor bath) and sipping on sake as snow falls on the mountain landscape all around you. While the Japanese are considered a modest people, mixed bathing was quite common until recent years and there are still some mixed rotenburo to be found.
The Japanese archipelago is located on one of the world's most active volcano fault lines. The drawbacks are obvious but the resulting abundance of naturally heated water, often rich in a variety of minerals with their associated health benefits, have been appreciated in Japan since ancient times. The word kamiyu, meaning "divine bath" refers to the healing powers of the onsen. Many people will make an annual two- or three-day visit to an onsen, with family, friends or co-workers. Company trips to onsen can become wild, raucous events as the combination of fresh air and too much alcohol bring out the party animal in many a salaryman.
The more popular spa towns are chock full of hotels, lodges and ryokans (traditional inns) and are always bustling during the winter months. Reserving your accommodation in advance is definitely recommended, especially on a weekend (though Japan has so many onsen that a day trip is also an option in many areas). Most places have their own in-house onsen, though in the smaller ryokan it may be little more than a standard bathroom, albeit with natural hot spring water. There are men's and ladies' areas, often distinguished only by kanji, so make sure you know the difference! The dressing rooms have lockers or shelves for your clothes (valuables should be left in your room) and may provide towels and toiletries, but it's best to check.
Once you've undressed, you enter the main bathing area. Birthday suit is the standard dress though the more modest bather will cover up with a towel. The most important thing to remember is that you must wash and rinse before you get into the bath. There are individual open "stalls", each with a mirror, shower hose and tap, basin, small seat and often shampoo and soap. Some larger onsen provide private shower stalls for the modest. Once you've washed and rinsed, you're ready to relax in the bath. There may be several different types, ranging from jacuzzis to mineral or even "electric" baths. Temperatures may also vary but are usually around 40-43°C. If you're wondering, that's hot! Those with high blood pressure or a heart condition, take heed. People will move around from one bath to another, with the highlight being the rotenburo. If you're lucky, it will have a view over mountain scenery or even the ocean. There are even rotenburo where you will be joined by wild mountain monkies!
Shougetsu Onsen, Hakone Yumoto
I've been to many onsen across the country, but one of the nicest was Shougetsu, in the popular onsen town of Hakone Yumoto. Hakone is one of the most famous onsen areas, and is convenient for even a day trip from Tokyo. Shougetsu is located close to the Hakone Yumoto station and is a popular spot for foreign visitors, especially as they have an excellent website in English. There is a selection of Japanese and western-style rooms, each with a lovely view of the mountains or the Hayakawa River. There are two main baths, one for women and one for men, though since one is a lot bigger they are rotated to give everyone a chance to enjoy them at their best. When I visited on a weekday, I had the huge bath all to myself. Now that is the height of luxury!
And the clincher for me was the food. It was as good as I've had at any restaurant in Japan. I lost count of how many courses there were, and by the time I'd settled into the very cool bar next to the restaurant, I didn't really care! And all this only an hour from Tokyo Station.
Hotellerie Maille Coeur Shougetsu website
You will most likely have been provided with a yukata, a light cotton robe that you'll find is all you'll need after your hot bath. Most onsen are located in mountain spa towns and other than bathing and taking in the scenery, often the only other activities available are eating and shopping. This source of income is of course vital to the survival of most of these towns. Popular souvenirs will vary by region but will usually include manju (sweet bean cakes), local handicrafts and, if the onsen is known for any particular health benefits, bath salts (nyuyoku-zai) and similar products.
But getting back to the eating...Many onsen resorts pride themselves on their cuisine, which is usually based around local and seasonal delicacies. Particularly during the cold winter months, a "nabe" is often the centerpiece. The word literally means a "pot" or "saucepan," but is used to refer to a hearty stew of meat or seafood cooked with an assortment of vegetables. But you may also have the choice of a western-style meal or be able to just order a la carte. At many onsen, you'll eat in the hotel restaurant after your bath and return to your room to find all the futons laid out for you. All you have to do is collapse and have the best night's sleep imaginable.
The urban equivalent of the onsen is the sento, public baths located in residential areas. They first became popular as Japan became more urbanized in the Edo Period (1600-1868) but have declined in number in recent years as apartments without bathrooms have become more rare (prompting the Tokyo metropolitan government to run a PR campaign including this poster citing the health benefits of negative ions). But for many people, mostly penny-pinching students and older people, they are still a source of community. The expression hadaka no tsukiai, meaning "naked companions", refers to this situation where, stripped of their outer garments all men are equal and people can speak their minds.