A secret hot spring deep in the mountains known only to a few. Even among hot spring enthusiasts, only a fraction are aware of its existence. Located in a place that is quite difficult to reach, visitors are rare. It is housed within an old, unmanned shack, where users pay by placing money into a wooden collection box. The bathing fee is 300 yen per person. There is only one bathtub, and it is not separated by gender.

It is a place where one can relax alone or visit as a couple. If you encounter other guests, please share the space considerately.

While it seems to be maintained by someone, the caretaker remains a mystery. The water has a thick, silky texture and is said to be "extraordinarily good."

It appears there are hidden benefits to the water.