The love of a hot bath has been a part of Japanese culture for centuries, in part because of the volcanic nature of the archipelago, which often means hot springs, also in part because of the Japanese love of communal activities, and ultimately because, what’s not to like? It’s a hot bath!
But as with many activities, the Japanese have refined the taking of hot baths into something approaching a ritual, and visiting Japan without visiting an onsen, or natural hot spring, is to have an incomplete visit to the country. We have addressed the rituals and manners of the onsen elsewhere on japanology.org, but there is another option that is more common, and more accessible – and considerably cheaper – than the traditional onsen.
The sento is a public bath akin to the hammam in the Middle East, where local people can go get a good bath for a reasonable price, usually around 450 yen, and half or less for children. And although they have been decreasing in number as more and more homes have their own baths since the 1970s, a visit to a sento is still enjoyed for its communal aspects, and a visitor would be wise to search out this simple, everyday pleasure.
With more than a thousand in Tokyo alone, the typical sento is tucked away in a residential district or small commercial area and is simple and utilitarian, as one might expect. Their layout is often similar, with high ceilings, an entry area with an attendant’s desk known as a bandai and two areas, separated by a relatively low (1.5 meters) wall, for men and for women. Sento feature many of the same items seen in a typical gym or bathhouse anywhere: A scale, a toilet, a changing area with lockers, some beverages and in many cases, beds for babies (but only on the women’s side). Joining these are typical Japanese items such as short stools and wooden buckets for bathing before entering the bath itself.
This last is an important aspect of any visit to a Japanese sento, onsen or even private home: Bathe first! This makes sense in any public bath, but the Japanese are adamant about it, even at home: One must already be clean when one enters the bath, which is for relaxation, not washing.
Public Domain, Link
The roots of the sento are in religious ritual bathing, which goes back as far as India, where bathing in Hindu temples was a rite of spiritual purification as much as a hygienic activity. As with much Asian culture, it migrated with Buddhism to China, Korea and then Japan, though surely anyone lucky enough to have a hot spring nearby didn’t need Chinese Buddhists to tell them that bathing in it was a good idea!
Nevertheless, it was in Buddhist temples that bathing got a foothold in Japan, more than a thousand years ago, during the Nara period, where they were first used only by monks and priests. But as time passed, more and more people were allowed to use them, and the first commercial sento is said to have been opened in the 13th century, in Kamakura. But it wasn’t until the Edo period of the 19th century that yuya (hot water shops) became common.
By Browne, George Waldo, 1851-1930 – Japan : the place and the people, Public Domain, Link
These days, most sento are chlorinated for health reasons, another way in which they are distinguished from onsen, which feature natural hot spring, of mineral-infused water, where additional chemicals are generally frowned upon. But sento are more practical institutions, and keeping out bacterial is a high priority when so many people use the water.
As with onsen, people with tattoos are generally barred from using the facilities, because of the long association by the Japanese of tattoos with gangsters, or yakusa. Visitors are often cut some slack in Japan, however, and those with subtle tattoos will probably have no problem. But if your tattoos can easily be covered with a bandage of some sort, you may feel less self-conscious about breaking this cultural taboo.
Because the genders are separated, most sento are entered naked, and wearing a bathing suit may strike the Japanese as odd. But children are allowed into the opposite sex’s bathing area generally until the age of eight, though some places still allow girls into the men’s until they are 13!
That said, women were long employed by sento to scrub men’s backs and otherwise serve them, and many sento were for a time associated with prostitution, though laws have long been established to discourage the commercial interaction of male customers and what were long called yuna (hot water women). This aspect was gradually shut down with the arrival of Admiral Perry and the Americans in the late 1800s, and has continued to be discouraged into modern times.
That said, by far most sento are neighborhood establishments, casual, inexpensive, utilitarian and made for the whole family, and should not be missed.