Illustrated Japanese Culture
温泉入浴
Onsen bathing uses water from a qualifying underground spring. A visit may mean a neighbourhood bathhouse, a day trip, a stay at a ryokan inn or a longer period of rest. The spring, the way its water is managed and the rules of the bathing facility all shape the experience.
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Japan’s 1948 Hot Springs Act covers water, mineral water, steam and certain gases emerging from underground. The source must be at least 25°C, or contain a specified substance at the required concentration. A cool mineral spring can therefore qualify. The 25°C threshold is not the required temperature of a bathing pool.
Groundwater can be heated by magma in volcanic areas. Non-volcanic springs include water heated deep underground and ancient seawater retained in geological formations. Sources may flow naturally or be reached by drilling and pumping.
Ryōyōsen is a classification within onsen, defined by temperature or chemical composition. Its ten categories are simple thermal, chloride, bicarbonate, sulphate, carbon dioxide, iron-containing, acidic, iodine-containing, sulphur and radioactive springs. A source may combine several characteristics. These names describe the water; they do not guarantee a cure for an individual’s illness.
Facilities display spring information and relevant treatments, including added water, heating, circulation and filtration, and disinfection. Kakenagashi usually describes water discharged after use rather than returned to the bath. It has no single nationwide legal definition and may involve added water or heating, so read the facility’s explanation.
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Ryokan often have communal baths, but some also accept day visitors. A kashikiri bath is reserved for private use during a time slot; a kazoku-buro, or family bath, is another common term for a private arrangement. Baths attached to guest rooms are a separate option. Check the water supply as well as the room description.
Many communal facilities separate baths by gender. Mixed baths and special facilities may require particular bathing garments. Tattoo policies also vary: some allow them, some require a covering, and others restrict entry. A reserved bath may offer a different arrangement.
An ashiyu is a footbath. At Atami Station, the municipal Ieyasu-no-Yu lets visitors soak their feet while sitting beside the water. It offers a different arrangement from the changing room and full-body bath.
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Leave clothes in the changing area and take a small towel to the washing area. Wash and rinse away soap before entering the communal pool. Kake-yu means pouring bath water over yourself to adjust to its temperature, starting with the hands and feet.
Keep towels and long hair out of the water. Follow the site’s clothing rules; ordinary communal onsen baths generally do not use swimsuits. Photography is prohibited in bathing areas. These shared-space rules help keep the pool clean and protect other bathers’ privacy.
Drink water before and after bathing, stand up slowly and leave the bath to rest if you feel unwell. Avoid bathing after drinking alcohol or when exhausted or ill. Children, older people and people with limited mobility should avoid bathing alone.
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The Nihon Shoki and regional fudoki record imperial visits and local uses of hot springs. Accounts of sacred or healing water helped shape the reputation of particular springs.
In the medieval period, aristocrats, monks and warriors travelled to springs and could stay for extended periods. Tōji combined repeated bathing with time away from ordinary routines. Accommodation and the settlement around the spring became part of that practice.
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During the Edo period, commoners increasingly travelled to hot springs. Guides and pictures of famous places presented destinations such as the seven springs of Hakone. Long stays for tōji existed alongside shorter sightseeing visits.
Publishers arranged spa names in ranking sheets resembling sumo banzuke. These popular comparisons promoted destinations and continued beyond the Edo period. They were not clinical assessments of the springs.
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Modern railways and other transport links made spa destinations easier to reach. The Railway Board’s 1920 hot-spring guide is one example of travel information prepared for this market. Scientific analysis and hygiene management also developed alongside holiday and recuperation travel.
From the middle of the Meiji period, Kazusa-style drilling helped expand well development in Beppu. Transport improvements supported travel. Steam-and-water separation equipment spread during 1955–64, contributing to the conspicuous steam landscape. Shared baths, lodgings and cooking with geothermal steam show several uses of the same local resource.
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The Ministry of the Environment’s 2017 “new tōji” proposal connects bathing with nature, local history, food and contact with the community. It adapts the idea of a restorative stay to contemporary schedules while longer-established forms of tōji continue.
Nyūtōzei is a local tax supporting uses such as sanitation, spring-source protection, fire services and tourism. Rates and exemptions vary by municipality and may differ between overnight and day visitors. Check the facility’s charge rather than assuming one national amount.
Not necessarily. It may qualify through the required concentration of a specified substance instead.
No. The legal temperature threshold is measured at the source.
Its composition and how the water is managed, including heating, added water, circulation and disinfection.
A bath reserved for private use during an allocated time slot.
At the washing area before entering the communal pool.
No. Keep it, and long hair, out of the bathing water.
No. They depend on the facility; check ahead.
It involves a stay with repeated bathing and rest rather than just one visit to a pool.
It ranked and promoted spas using a format associated with sumo rankings.
No. Municipal rates and exemptions vary.