Awanoyu

Stayed as a ryokan guest. The place is absolutely amazing. The surrounding area is also cool — you can encounter wild monkeys. The food was great too. If you book a double room for one person, you can ask for a double kaiseki and they'll honestly give it to you. As for the baths: in the main area (men's side), there are two indoor baths. One with clear water and below-average temperature, the other milky and hot. There's also a small additional third outdoor milky bath with below-average water temperature. The main feature of the ryokan is of course the large mixed outdoor bath. I didn't take photos — there are plenty on Google, the internet, and even in the Matsumoto museum. The water is densely milky in color with a noticeable smell, and the temperature in the mixed bath is mild. You can honestly just hang out there for hours, moving around the bath and under the water streams. You really need to book a room with an overnight stay. At night it's absolutely heavenly to lie in the big bath all alone, snow all around, stars on the black sky — like something out of a fantasy. Since you end up spending hours in the bath, the changing crowd can actually add variety. At one point in the evening, a grandma shooed out a grandpa and about 5-6 young Japanese women, directing their movements around the bath. The women are given bathing clothes, so everything is decent. For men — because of the dense milky water, nothing is visible, and entry/exit is also relatively modest. If you compare baths head to head, this one is of course the best out of all 45 onsens/ryokans on this trip.