A Hidden Retreat in the Mountains of Oku-Ureshino Onsen
The spring water here has a pH of 7.48, which is very close to human blood (pH 7.35–7.45).
That means it is naturally gentle on the body and easy to absorb.
It also contains 116mg of metasilicic acid, often called a “natural moisturizing ingredient.”
Because of this, I felt my skin becoming softer and smoother after bathing—like the water itself was taking care of me.
What surprised me even more is that at Sentorou, they don’t just use this pure water for the hot spring baths.
All the drinking water and even the meals are prepared with the same spring water.
For me, that makes this ryokan very special—a place where you can truly feel the blessing of water in every detail of your stay.
Nature in Oku-Ureshino
Looking over the calm lake reflecting the lush green mountains, I felt the noise of everyday life fade away.
In June, fireflies dance above the clear streams, creating a magical scene of light, while in November, the mountains turn into a canvas of brilliant autumn colors.
Each season reveals a different charm, and the quiet time spent at the ryokan allows me to truly feel the richness and beauty of nature all around me.
Pure Water - Sennensui -
The name “Sennen-sui” carries a profound meaning.
In Japanese, “Sen” (千) means “a thousand” or “countless,” symbolizing abundance and continuity.
“Nen” (念) refers to “thoughts,” “prayers,” or “heartfelt wishes.”
Together, Sennen-sui can be understood as “the water of a thousand prayers and wishes.”
It represents pure spring water that has quietly flowed through time, holding the hopes of people and nourishing their daily lives.
One of the things that left a deep impression on me at Sentorou was the spring water called Sennen-sui.
This underground water flows directly within the grounds of the ryokan, and it has been cherished by locals for generations.
What makes it remarkable is its quality.
The water is gentle, with a pH close to that of human blood, and it is rich in minerals that are said to be good for both health and beauty.
At Sentorou, this pure spring water is not only used for bathing, but also for drinking and cooking.
For me, tasting the meals and tea prepared with this natural water was as memorable as soaking in the hot spring itself.
Sennen-sui is more than just water—it is part of what makes this ryokan so unique, a hidden place where nature quietly supports daily life.
The Flow of Change
Perhaps it is important to cherish the nature that still remains.
Or perhaps there is no need to hold on too tightly—because, just like human beings, nature itself is meant to change.
Maybe that is what nature truly is.
What strikes me is how quickly these changes are happening today.
How should we understand this accelerating speed?
If things continue this way, where will it lead us?
Humans are not fixed creatures; we are always changing, always evolving.
So maybe there is no absolute “good” or “bad” in this process—only the flow of change itself.
Relaxing in Sentorou’s Rotenburo
One of the most memorable experiences I had at Sentorou was bathing in the open-air hot spring bath, or “rotenburo.”
In Japan, rotenburo are deeply cherished, not just as places to bathe, but as places to connect—with nature, with the seasons, and with oneself.
Soaking in the warm water while breathing in the fresh mountain air, I felt the boundaries between myself and nature disappear.
In summer, I could hear the flow of water and even imagine fireflies in the night sky; in autumn, the colors of the leaves reflected in the steam made the bath feel like a painting.
For Japanese people, hot springs are more than just relaxation—they are part of daily life, tradition, and healing.
The water itself is treated with deep respect, because it is believed to carry the blessings of the earth.
At Sentorou, this water comes directly from their own spring, rich in minerals and purity.
To me, the rotenburo here was not only a bath, but an experience of how precious water is—something that sustains life, nurtures beauty, and brings quiet peace to the heart.
My Way of Enjoying Sentoro
When I stayed at Sentorou, I discovered that everything begins with the water.
From the crystal-clear spring called Sennen-sui to the soothing hot spring baths, the ryokan is deeply connected to nature’s gift of pure water.
My favorite moment was soaking in the open-air bath (rotenburo).
Surrounded by mountains, breathing in the fresh air, and listening to the sound of flowing water, I felt an incredible sense of peace.
In summer, I imagined fireflies glowing in the dark, and in autumn, the reflection of red and golden leaves in the steam made the bath feel like a painting.
Inside the ryokan, the atmosphere is calm and timeless.
Meals and drinks are prepared with the same pure spring water, and every detail seems to carry the quiet spirit of the surrounding nature.
For me, Sentorou is not just a place to stay—it is a hidden retreat where water, hot springs, and silence create a harmony that heals both body and mind.
Why I Recommend This Place
The most remarkable thing about Sentorou is the water.
Many hot springs have clear water, but the water here is not only clear—it has a rare purity, completely free from any heaviness or aftertaste.
That kind of transparency is truly uncommon.
I have soaked in countless hot springs across Japan, yet this level of clarity and freshness is something I had almost never experienced before.
Each bath felt as though the water was gently cleansing both body and mind.
What makes it even more special is that guests can take the water home.
Using this pure spring water for sake or cooking brings out flavors in a way that ordinary water cannot.
Sentorou remains unforgettable to me because of this water—so pure, so rare, and so deeply connected to the land.
Ryokan Sentoro
Address:
〒843-0304
佐賀県嬉野市嬉野町大字岩屋川内乙２１１７−１
Tel:
0954-42-1195
Please note that reservations can only be made in Japanese.
Opening Hours :
Open for Non-overnight Guests: 6:30 PM – 9:00 PM
Notice
Reservation required.
Please note that we may be closed on Japanese national holidays or due to other circumstances.
If you would like to confirm our opening hours in advance, feel free to contact us via WhatsApp or LINE, and we will be happy to inform you.
