Kutsurogi no Yado Paru

This small inn in Norikura Kogen has four baths fed by natural onsen water, two indoor and two outdoor, and all of them are booked as private kashikiri (貸切) baths rather than shared gender-split rooms (the indoor ones only switch to gender-split bathing when things get busy). The water runs milky white, part of the Norikura Kogen Onsen (乗鞍高原温泉) group, so each soak looks a bit different depending on the light. It's a family-run pension rather than a big ryokan, closer in feel to a minshuku (民宿): a lounge with a wood stove for evenings, birds kept on site, and rooms set among birch trees where the loudest thing around is usually a bird call.