Mikagura Onsen Beech Inn Koase

The open-air bath is a private, reservation-only tub set among beech trees; it closes for winter. Its water is steeped with wild herbs, dokudami, mugwort and mint among them, that staff gather themselves from the surrounding mountains and dry in the sun. By day you look out over the valley; at night the stars fill the sky. Indoors there is a separate bath for men and women, and a wood-built sauna, renovated in 2024, where you pour water over the stones yourself to raise the heat. The spring water feels soft and smooth on the skin. Koase is a small, six-room ryokan, the only inn at Mikagura Onsen, alone in the beech forest; guests without a car can arrange a pickup by microbus. Meals lean on the same mountains: handmade soba, salt-grilled river char, wild vegetables, and rice from the inn's own paddies, with vegan meals available on request. A year-round campground shares the grounds, with gear rental for anyone arriving empty-handed.