We stayed at the inn of the Japan Association for Secluded Hot Spring Preservation, KIYASUYA, a mountain inn in Oita Prefecture Sujiyu Onsen. All rooms have a separate open-air bath, and meals are served in a completely private room, making it a truly restful inn. This was our second visit, following last year, and we had a relaxing stay at this inn, where every detail of the rooms has been carefully considered, not to mention the 24-hour open-air bath, and the hospitality of the staff was very pleasant.