This sprawling, family-run 1930s inn has wonderfully preserved Japanese rooms and well-chosen art and furnishings evoking periods from art deco to today. The stone-and-tile onsen and private rotemburo are so lovely you'll hardly mind that only a couple of the eight rooms have full bath and toilet; two others have toilet only.
If you'd like to drop by just to use the baths, day use is ¥500 to ¥700; baths are open 11am to 3pm.