
A mysterious outdoor onsen leaves a lifelong impression on two night-time visitors.
In Japan, 26 June is Rotenburo Day (Open-air Bath Day), due to the double meanings in the syllables that make up the word “rotenburo”, with “ro” sounding like “roku” or “six”, “ten” being the word for a decimal point used between numbers, “bu” being an alternate reading of “fu”, or “two”, and “ro” being “six”, giving us the date “6.26“.
While most people would let this day pass them by without even knowing of its existence, onsen lovers use it as an excuse to get out there and take a soak in the great outdoors. Our reporter Seiji Nakazawa is one of those people, but as he was in the office working late and unable to sink into a rotenburo like he wanted, he decided to share a memorable rotenburo experience with us instead.
Having visited dozens, if not hundreds, of hot springs in his lifetime, Seiji is something of an onsen connoisseur, so for a bath to stand out for him, it has to be special. When he told us the hot spring was called Yudomari Onsen, in Yakushima — a World Heritage-listed island said to be one of the inspirations for the Studio Ghibli movie Princess Mononoke — we immediately added it to our bucket list.
▼ Yakushima is world-famous for its pristine forests.

According to Seiji, there are a couple of things that make this outdoor bath memorable, with one being the cost, because at 300 yen (US$1.87) per visit, he believes it’s one of the cheapest rotenburo in all of Japan. However, as with many special travel experiences, it’s the way he discovered the hot spring that makes it stick out in his mind, as well as the onsen itself, because it’s like nowhere else he’s ever visited.
The story begins when Seiji visited the island a couple of years back, and instead of staying in the large town of Miyanoura in the north, where most tourists tend to congregate, he stayed on the opposite side of the island, in a guesthouse in the middle of nowhere.
▼ When he arrived in the area without knowing anything about Yakushima, he found that there were no towns or private houses.

Truly in the middle of nowhere, Seiji found himself alone in the dorm until his third night there, when a guest, whom we’ll call Mr M, arrived. Seiji usually keeps to himself in shared accommodations, but his quiet surroundings made him long for company, so he found himself opening up to his dorm mate soon after meeting him. Mr M said he’d come to take photos of the starry skies, and he’d rented a car so they started talking about going somewhere together. However, the nights in Yakushima are dark and the stores close early, so by the time they got to talking about it, most of the stores had already closed.
Seiji used his phone to search for things to do nearby, and that’s when he discovered there was a really cheap hot spring in the vicinity…and it was open 24 hours a day. Seiji couldn’t believe there was a hot spring open at all hours of the day and night in such a remote location, and when he told Mr M about it, they immediately headed out to find it.
It was eerie driving along roads with no streetlights, and Seiji feared he might be spirited away by magical beings hiding in the darkness. However, sure enough, after a short drive, the two new friends arrived at their destination.
▼ Yudomari Onsen (“湯泊温泉”)

After walking through the lit entrance, there were no other people around, and no other lights either, which made him wonder what type of onsen they were visiting. But then, as they walked further down the path, they soon found that this was no ordinary onsen — in fact, it looked more like an abandoned hot spring.
▼ Is…is it really okay to bathe here?

Feeling a flutter of excitement in his onsen-loving heart, Seiji examined the site more closely and found that it was absolutely fine to bathe here, with a box set aside for visitors to pay the bathing fee. Popping his coins in and stripping off his clothes, Seiji felt the nip of the night air and realised they were incredibly close to the shore, with the sound of crashing waves cutting through the quietness.

Slinging his clothes over a nearby rock, Seiji slid naked into the water, which felt slightly slimy and lukewarm. He could hear the sound of Mr M stripping off somewhere on the other side of the darkness, but he couldn’t see him at all, and after he heard his friend slide into the onsen, there was no other sound but the crashing of the waves in front of them.
“The stars have appeared,” Mr M eventually said after they’d been sitting in silence for a while. When Seiji looked up, he saw that the stars were indeed shining bright, although they were piercing through gaps in the clouds. “Just a little bit more,” Mr. M said, as if trying to coax them out from the cloud cover, and Seiji found himself replying, “Ah, what a shame.”

There was no real meaning in the exchange, but that was exactly what Seiji liked about it. They were just two men stopping to acknowledge the beauty of the universe around them, and though it made them feel small in their existence, there was real comfort in knowing they weren’t totally alone.
As they sat back and gazed at the stars, Seiji felt like he wanted to immerse himself in this extraordinary life forever. Before he knew it, the sound of the waves had turned into soothing background music, and he felt at one with nature and the universe.
▼ Judging by the site on Google Maps, it turns out Yudomari Onsen is really by the sea.
Two years have passed since that serendipitous night when Seiji met Mr M and struck up a friendship, and he often finds his thoughts drifting back to that blissful soak in the outdoor hot spring. It’s his way of de-stressing and remembering not to sweat the little things when busy city life gets the better of him in Tokyo, and for him, that’s the real power of this secret rotenburo.
Onsen information
Yudomari Onsen / 湯泊温泉
Address: Kagoshima-ken, Kumage-gun, Yakushima-cho Yudomari 1714-28
鹿児島県熊毛郡屋久島町湯泊1714-28
Open 24 hours
Website (Yakushima Tourist Association)
Photos ©SoraNews24
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[ Read in Japanese ]

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