On June 7, 2026, KAI Kusatsu, a ryokan under Hoshino Resorts’ hot-spring inn brand “KAI,” will open in Kusatsu Onsen, the famous hot-spring town of Kusatsu, Gunma Prefecture.
Kusatsu Onsen is one of Japan’s most representative hot-spring destinations, known for its abundant hot-spring water and the lively atmosphere of its onsen town. “KAI Kusatsu” places its accommodations on a nature-rich site on elevated ground with views toward Mt. Kusatsu-Shirane, ensuring a calm and relaxing stay environment.
At the same time, the accommodation area and the Kusatsu onsen town are connected by a guests-only tunnel, enabling visitors to switch between the quiet, elevated environment and the town’s sightseeing and strolling areas as needed. The ability to enjoy both a nature-immersed stay and experiences in the onsen town is a defining feature of this property.
Three Key Highlights
1. A “Forest Hot-Spring Inn” and the Onsen Town Connected by a Tunnel
The concept of “KAI Kusatsu” is “A forest hot-spring inn and the onsen town connected by a tunnel.” Guests can spend peaceful time in the accommodation area on elevated ground surrounded by nature, and when they wish, pass through the tunnel to stroll and sightsee in Kusatsu’s onsen town. Being able to switch between tranquility and bustle within a single stay is a distinctive appeal of this inn.
2. 94 Guest Rooms and a Variety of Hot-Spring Experiences
The property offers a total of 94 guest rooms, including rooms with private open-air baths. Some room types allow guests to enjoy expansive views toward Mt. Kusatsu-Shirane and an open, airy hot-spring experience without leaving their room. Guests can enjoy Kusatsu’s hot-spring waters in the on-site large public bath and the “Yugoya” bathhouse building, and by passing through the dedicated tunnel, they can also immerse themselves in the hot-spring culture around the Yubatake area.
3. Diverse Dining with Local Ingredients, Including a Soba Kappo
Dinner will feature a Japanese travel kaiseki course that brings out the food culture of Jōshū (Gunma). In addition, the site will include “Soba Kappo SAI,” Hoshino Resorts’ first soba kappo concept, offering a wide range of culinary experiences such as 100% buckwheat soba made from local stone-milled flour (juwari soba), small plates, local sake, craft beer, and natural wine.
Surroundings
Kusatsu Onsen, where “KAI Kusatsu” is located, is a tourist destination known for its abundant hot-spring water and historic onsen town. From the elevated accommodation area, guests can enjoy the nature around Mt. Kusatsu-Shirane, and they can access the town center on foot or via the tunnel. Nearby, visitors can also enjoy:
- Yubatake — Kusatsu’s iconic sightseeing landmark
- Sainokawara Park & Open-Air Bath — A large open-air bath harmonizing with nature
- Restaurants and souvenir streets in the onsen town
- Strolling the onsen town and enjoying an onsen-hopping experience
This location is drawing attention as an attractive destination where visitors can enjoy both Kusatsu’s hot-spring culture and mountain nature at the same time.
Access
Address: 464-690, Kusatsu, Kusatsu-machi, Agatsuma-gun, Gunma 377-1711, Japan
Train + Bus
Take the JR Agatsuma Line to “Naganohara-Kusatsuguchi Station,” then use a route bus bound for Kusatsu Onsen to access the Kusatsu Onsen area.
By Car
From the Kan-etsu Expressway “Shibukawa Ikaho IC,” head toward Kusatsu Onsen via national routes.
As the property is located in a highland area, caution is required in winter due to snow accumulation and icy roads.
