Hoshino Resorts KAI Sengokuhara shared by @cntraveler says: ""The KAI Sengokuhara, an upscale ryokan from Hoshino Resorts, often sells out year-round, perhaps because it has just 16 guest rooms, and each comes complete with its own private outdoor onsen, which is a luxurious rarity in Japan."" on Postcard