14 of the 18 rooms have an open-air bath (including a half-open-air bath).
Rooms with open-air baths
Oborozuki / Aoi Tsuki / Mikazuki / Eboshi-dake / Byobu-dake / Katta-dake / Sugi / Momiji / Nazuna / Tsumekusa(Semi-open-air bath) / Nanohana /Mizutama / Mizumari / Ito-tombo