Onsen, a Japanese wellness ritual

Lanterns cast a dim light over neatly trimmed garden plants and shrubs. A ginkgo tree sifts sunlight through its foliage. Elegant maple trees with red leaves, both vibrant and delicate. A moist, green slope of ground-hugging moss. Spring water trickling down a stack of rocks, moving slowly, stone over stone into stone; a discreet soundscape so constant it begins to sound like silence.

Water. Undercurrents stirring, ripples on the surface, hot steam slowly rising and misting the skin as you wade in.

Long exhales.

Sitting on underwater rocks, immersed in warm water, watching the serene garden and letting thoughts drift off in peace.

Minimalist.

Zen.

Spa rituals around the world look very different, and over time I will explore many of them in this newsletter. Travelling through Japan I found myself seeking out the same ritual everywhere. Visiting onsen (温泉 hot springs) and sentō (銭湯 public bath houses), a wellness tradition and art that Japan has been perfecting for more than a millennium. Deeply woven into the daily fabric of Japanese life, this was not a spa trip, but hot springs became part of understanding the country itself.

Located on the Pacific Ring of Fire, a highly active seismic zone, Japan sits on four tectonic plates that move, causing the formation of magma that can erupt as lava. When cracks also form through the plate movements, water seeps below and pools into reservoirs. Subsurface magma heats the groundwater, and it rises back up to the surface forming mud pots, fumaroles, geysers or hot springs.

Japan is home to 7% of the world’s active volcanoes, a staggering 110 of them. The country also has ~25,000 hot springs. Approximately 3,000 can by law be called real ‘onsen’ as they have the government specified amount of minerals like sulphur, sodium, iron, or magnesium, and a temperature of +25°C or above. The physical health benefits each offers through its therapeutic water, explains why specific onsens became revered destinations for tourism.

The history of onsen spans over 1,300 years, before the Nara period’s Buddhist and Shinto purification rituals, and emperors visiting them as retreats of prestige and therapeutic healing. In samurai society, bathing in volcanic waters served for both nobility and warriors to find relaxation, healing, and rejuvenation. During the Edo period, towns were built around hot springs that commoners could travel to for social relaxation. It became a way to purify the spirit, improve health, and foster ‘naked association’ (Hadaka no Tsukiai), suggesting that nudity reveals equality, where social barriers are lowered, thus permitting genuine connection.

One of the most memorable experiences I had were in Kinosaki Onsen, a natural hot spring town in the western part of the country, near the Sea of Japan. There, I stayed at a local ryokan (旅館 a traditional Japanese inn) called Akaishiya with a history of 230 years. I interviewed Akaishiya’s new owner and CEO, Mr. Kazuya Imazu and his hotel manager Hiro-san. With over three decades of family ryokan experience, Mr. Imazu today holds directorships of both the Kinosaki Onsen Ryokan Association and the Japan Ryokan & Hotel Association.

With seven bath houses where the public can freely enjoy natural onsens, people describe this town as “one large ryokan”. Visitors can view each ryokan as a guest room, the streets as corridors, and all shops, restaurants, and bars functioning as public facilities of one hotel. The local ritual is to go onsen-hopping, focusing on one’s bathing and also taking a digital detox. The dress code is a traditional yukata robe (浴衣 light cotton kimono) and geta (下駄 wooden sandals), essentials are carried in a basket — all provided by accommodation hosts. While yukatas are pyjamas typically not worn in public, here they are considered appropriate attire as the entire town is part of one ryokan.

During sakura season this spring, the town is gearing up for celebrations of its anniversary from April 23rd to 24th, 2026. Imazu-san explained what to expect from the traditional events: “Kinosaki’s annual Onsen Festival commemorates the work of Dochi Shonin, a Buddhist monk who founded Kinosaki Onsen over 1,300 years ago. On the day of the Onsen Festival, ceremonies are held at Onsenji Temple, which enshrines the founder of the temple, Dochi Shonin, including a prayer service and a procession of children.

Also, on this day, Kinosaki's public bath houses are open to the public free of charge, and many stalls line the road in front of Akaishiya, attracting visitors from outside town. Kinosaki has a well-known folktale about the founding of Kinosaki Onsen, and for us, the Onsen Festival is an event that evokes that folktale. I believe that the Spring Onsen Festival and the Autumn Grand Festival, held annually from October 14th to 15th and the participation of all townspeople, greatly contribute to the development of people who protect and pass on the town's culture. Looking at my friends who grew up in Kinosaki from a young age, I think that a strong sense of civic pride is fostered through these historical festivals and various events, which allow the locals to connect with each other.”

With Akaishiya’s long-standing presence, and the wide-spread healing promise of onsen, I was curious about what wellness change returning guests experience during their time spent in Kinosaki Onsen.

Mr. Imazu shared: “We believe that the most memorable aspects of a pleasant trip are the interactions with local people. Especially when it comes to interacting with people living in a different culture and country. No matter how advanced technology becomes, this is an irreplaceable and precious experience. That experience will eventually be etched into your heart as a rich memory that enriches your life.

Such rich memories heal the soul. And we believe that healing the soul is the essence of a true retreat.

It is through human interaction that the heart is filled with contentment.

Longer stays offer even more opportunities for such interactions. While we may not be able to bring about any grand transformations in our guests' lives, our wish is that those who visit Kinosaki feel that they have received spiritual rejuvenation.”

Hosting ~700,000 visitors every year is no small feat for a small town. I asked about what the team of Akaishiya as guardians of tradition wish for.

Mr. Imazu was both cautious and pragmatic in his reply, touching on how the quality of tourism matters: “If I were to point out one challenge, it would be the concern that Kinosaki's immense popularity might lead to economic priorities taking precedence and cultural value being destroyed. Kinosaki has a history of upholding a kind of localism, run by local capital and residents, and its greatest strength has been that, despite being a tourist destination, people genuinely live there. However, the situation is changing somewhat. With the extreme rise in land prices being a major factor, it's becoming increasingly difficult for new businesses to enter the market with local capital. When companies with strong capital from outside catch a whiff of business potential, they enter the market. If everything becomes generic, the region's unique character will be lost. If people who show deep love and understanding for the local area are excluded, the culture will be destroyed. I believe this is a future that absolutely must not be allowed.

Akaishiya’s manager Hiro-san added “Kinosaki has kept the tradition and also changed for the future.”

They pondered upon how local residents coexist wonderfully, how there is mutual respect and pride about the town. Of course, heritage comes with responsibility. Keeping the legacy for future generations in mind; real collaboration is needed across both preservation and modernisation tactics.

“It's not just about creating a system of economic circulation based on coexistence and mutual prosperity, but also about passing on a shared spirit. Kinosaki Town offers opportunities to pass on stories to children and grandchildren without even realizing it. In Japan, the declining birthrate and aging population are progressing at an extreme pace, especially in regional cities. Kinosaki Onsen is no exception, and we feel a great sense of crisis. However, if a town doesn't have any appeal, no one will want to visit or live there, so all we can do is think about how we can make it a more attractive town and build it up steadily. We believe that our task is to create a town where visitors, residents, and people who work there can all live happily, with the strong tool of hot springs at the centre.”

To better understand how Japanese onsens and bath houses are uniquely different to retreats, spas and other hot spring experiences around the world, Imazu-san offered his perspective: “This might be a bit conceptual, but if I had to sum it up, I'd say it's about being "analog." I personally believe that humans aren't logical enough to judge things in terms of 0 or 1, and that human evolution isn't as fast as technology.

I think that experiencing, feeling, and understanding things requires a certain amount of time. There's a big difference between understanding something by listening to someone else's story and actually seeing it with your own eyes, and the depth of emotion you get from actually experiencing something yourself is even greater. Hot springs and public baths can't be carried around like digital tools, nor do they have the beautiful, perfectly crafted finish of a virtual experience.

To truly experience the warmth and comfort of the water on your skin, and the various sensations you feel with your five senses in that moment, for now, the only way is for people to come and experience it for themselves.

When you enter a warm Japanese bath — especially one that might be too hot for people from Northern Europe — you naturally let out a sigh, a kind of exclamation of admiration, but this is something that can only be conveyed by experiencing it yourself.”, Mr. Imazu explained.

“Even if one day our five senses are analysed and everything can be virtually replicated, I believe that the act of bathing — which not only solves hygiene problems but also brings relaxation to the mind and body — cannot be fully replicated. The comfort of lying in a large bathtub is something that can be shared not only by Japanese people but by people all over the world, and I think it is irreplaceable.

In a world where things change at an alarming pace, people are under extreme tension. I'd like to suggest to everyone in the world; "Let's all take a big bath, relax, and think things through!"

There is an intimate atmosphere in Kinosaki and I found myself quickly charmed by this very picturesque place where everyone has the same knowing smile. Instantly slowed down by clippety-clopping small steps, visitors take their time moving across small canal bridges. Leaning over the edge I saw colourful Koi carp passing underneath. Time in Kinosaki Onsen felt unhurried and like a true haven for wellness. As I dipped in and out of the bath houses, adapting to traditional etiquette rules, it felt less like observing Japan, and more like briefly living one of its oldest daily rhythms from within, where bathing, movement, and interaction were in flow.

My personal favourite onsen in Kinosaki was the Goshono-yu, also known as the “Water of Beauty,” where the water is said to bring protection against fire, and luck in love. There, set by a garden, moving within the ritual felt like true immersion in nature. The men's and women's areas were rotated daily, so every guest, regardless of when they visit, could experience the same view.

Long before wellness became an industry, Japanese hot springs called for calming disciplines in life. That is also what makes the power of onsen so timeless: presence and patience in an ancient wellness ritual where nature continues to be the healer.