Norikura Kogen Onsen Namiki-so

Namiki-so is a small minshuku in Norikura Kogen with a gender-separated indoor bath and one outdoor rotenburo. There's no mixed bathing here: the rotenburo just switches between men and women through the day on a sign-based rotation. The water is milky white sulfur onsen water, kept flowing straight from the source rather than diluted (kakenagashi, かけ流し), and one guest who knows both baths well said it's close to the water at Shirahone Onsen, on the other side of the mountain. It's a small inn run by a single proprietress, known for hearty home cooking and a clear view of Mt. Norikura from right outside, the kind of place regulars keep coming back to.