An open air hot tub is called a roten-buro. Bathe in the great outdoors and your spirit will feel released. (Ashinomaki Onsen Spa, Fukushima Prefecture)

This steaming water gushes from the ground, a true blessing of nature.

This 19th century ukiyoe woodblock print depicts a woman enjoying a hot spring cure in Hakone. Tokaido Meisho E series entitled Tokaido Hakone Toji (Famous Views of the Tokaido: Hakone Hot Springs). (Property of the Tokyo Metropolitan Foundation for History and Culture Image Archives)

Hot springs are the best source of soothing comfort for the Japanese. Especially favored are open air baths, with the sky above and nature all around. There you can commune with nature, and you might even feel at one with the grand scheme of things, immersed in water.

A mountain stream whispers in the ear, a kindly breeze caresses the bare skin, aromas from the mineral waters of the spring waft to the nose... The leaves on the trees, so green and fragrant, turn to brilliant colors if it’s in late autumn, then flutter down.

Perhaps the reason open air bathing holds such an appeal is that our genes might be ingrained with the ability to reset our five senses when we bathe in the bosom of nature. Ruins unearthed in Nagano Prefecture in 1964 suggest that the Japanese have had a relationship with spas for a good 6,000 years.

I think of a shower as one aspect of the West’s “wash and rinse away” culture, and of the Japanese love of soaking up to the shoulders in a hot tub as one aspect of Japan’s “soak in comfort” culture. This may suggest the true comfort found in hot springs.

Japan’s indigenous religion, Shinto, uses the word kegare to describe immorality or impropriety. Defilement can be cleansed with water in a purification ritual called misogi. Doing misogi at a hot spring was called yugori. It would seem that the custom of spa bathing was motivated by a desire not so much to wash grime from the body but to cleanse the mind and spirit through yu-go-ri (literally, “spa water to abandon defilement”).

In the old days, the misogi ritual was closely tied to a belief in the revitalization that occurs by becoming a new self. Revitalization makes one young again. Hot springs have long been regarded in Japan as a way to rejuvenate. Modern science tells us that the antioxidant power in mineral waters can reinvigorate cells, providing an anti-aging effect. As we grow older our cells become more susceptible to oxidation, and “cellular rust” forms. On the other hand, bathing in spa waters can take away this rust by reducing oxidation. The high antioxidant effect rejuvenates, as science shows.

“At a hot spring, rise above your consciousness and follow Mother Nature.” This maxim appears in 19th century guidebooks extolling the therapeutic benefits of spas. For me, it expresses an awareness of the healing power of a hot spring. Its steaming waters, born from the energy of the planet, are pure, and perhaps we would do well to develop a better frame of mind by soaking ourselves in them. It might be worthwhile to practice a “Way of Hot Springs,” preparing for a bath at a spa while striving for muga, a state of mind without egotism, without worldly thoughts—in other words, attaining a spiritual state of perfect selflessness, called mushin in Buddhism.

So, how about coming to Japan to soak in a hot spring?

Matsuda Tadanori
Matsuda Tadanori is a doctor of medicine and an expert on hot springs. He is currently professor at the Mongolian National University of Medical Sciences. Author of Edo no Onsen-gaku (“A Study of Hot Springs in the Edo Period”), Onsen Kyoju no Tojiryoku (“Professor Hot Springs and Spa Healing”), Onsen Kyoju no Nihon Hyakumeito (“100 Great Spas Recommended by Professor Hot Springs”), and other works.