Hoshino Resorts to open Kai Zao in Yamagata Prefecture

Hoshino Resorts is set to open its 26th facility under the Kai brand, Kai Zao, in the Zao Onsen area of Yamagata Prefecture on October 15, 2026. This marks the company's first expansion into Yamagata.

The facility features a unique 14-sided tower architecture designed to offer 360-degree views of the surrounding mountains. The wellness concept, titled “Okama de Totonou, Onsen Spiral,” utilizes the region's highly acidic sulfur springs. To ensure a comfortable experience, the hot spring concentrations are offered in three stages: a 0% concentration bath, a 50% diluted bath, and a 100% pure source bath.

Guests can access a rooftop garden equipped with a jet bath inspired by the Okama crater, alongside saunas and cold baths. The dining experience focuses on local ingredients, featuring the “Gassan Nabe” duck and mushroom hot pot. The guest rooms incorporate local craftsmanship, including furniture from Tendo Mokko and traditional safflower-dyed decor.