Luxury ryokan brand KAI has opened their latest onsen hotel in Gunma Prefecture, northwest of Tokyo, in a town home to one of Japan’s Three Famous Hot Springs.
KAI Kusatsu is the latest of KAI’s ’30 Onsen Ryokans, 30 Onsen Cultures’ mission to have 30 properties under their banner by the end of the decade, and this one in the village of Kusatsu promises to be one of the most unique.
What makes Kusatsu Town special?
The mountain town of Kusatsu boasts one of the biggest flows of naturally heated spring water in Japan (around 32,000 litres flow from Mount Kusatsu-Shirane every minute) meaning this beautiful alpine onsen has one of the most concentrated number of public and private bath houses in Japan.
What’s more, the sulphur-rich, naturally low pH water helps with skin toning and exfoliation, and is said to increase blood circulation and metabolism.
Because Kusatsu is quite compact, the village is perfect for a romantic evening stroll in your traditional yukata gown, exploring the onsen baths and eateries around the village.
KAI Kusatsu onsen ryokan
KAI Kusatsu blends the authenticity of a traditional ryokan with modern comforts and elegant luxury to create a serene Japanese experience in one of the country’s most venerated spa towns.
Guest rooms across the KAI brand’s properties feature signature rooms that reflect regional culture. At KAI Kusatsu, the ‘Silk Art Rooms’ honour Gunma Prefecture’s heritage of silk production.
Designed by internationally acclaimed textile artist Reiko Sudo and crafted using traditional Kiryu weaving techniques, rooms seamlessly blend artistry with comfort. Silk lampshades, custom cushions and bed runners inspired by alpine flora create a soft, harmonious atmosphere throughout the space.
What’s more, guests can get hands-on with Gunma’s cultural connection to the silk industry. KAI Kusatsu’s ‘Joshu Zaguri Silk Spinning Experience’ includes learning how to use traditional zaguri hand tools to spool silk threads from cocoons and making a souvenir tassel from the silk. These techniques date back to the Edo Period (1603-1868) and bring the region’s culture firmly into focus for visitors, giving greater appreciation for the artworks throughout the resort.
In-house onsen and post-bathing experiences at KAI Kusatsu
KAI Kusatsu’s bathhouse features a range of open-air and indoor onsen baths filled with water from two natural springs with their own unique mineral properties and temperatures, allowing guests to fully experience the natural benefits of Kusatsu Onsen.
The first is the Bandaiko water course, known for having some of the highest discharge volumes, temperatures and acidity levels in the region. The second is the Nishinogawara Spring, a rare, milder acidic water source utilised by only a limited number of facilities.
For an after-soak experience, guests can unwind in the beautifully appointed Fireplace Lounge. The elegant fireplace is central to the room with its four distinct zones. Guests can choose where to relax while the wood fire crackles and warms this sublime space.
KAI Kusatsu’s private tunnel to town
Connecting the serenity of the ryokan to the lively town beyond, KAI Kusatsu has a tunnel, solely for resort guests, which comes out close to the action of Kusatsu Onsen.
From here guests can explore the town, see the springs as they flow over their stony riverbeds, experience the incredible range of public onsen baths and try local cuisine in the many eateries of Kusatsu.
In fact, KAI Kusatsu guests can purchase a ‘Town-Strolling Kit’ as part of their stay, encouraging them to go out into the town in traditional yukata gowns and get a feel for Gunma’s culture. The kit is a furoshiki bag with a Three-Bath Strolling Pass that gives access to three of Kusatsu’s most iconic onsen: the authentically traditional Goza no Yu, the ultra-low pH Otaki no Yu and Nishi no Kawara Open-Air Bath — one of Japan’s largest outdoor hot spring baths.
The town-strolling kit also contains a guide curated by the staff at KAI Kusatsu and highlights local favourite spots, insider tips and recommendations for dining, and other experiences around the town.
Dining at KAI Kusatsu
Guests at KAI Kusatsu can choose between two primary dining pathways: Joshu Hoden Kaiseki and Tejiko Nama-ko-uchi Soba Kaiseki. Both are kaiseki formats, meaning a traditional Japanese multi-dish meal that progresses through a set menu.
The Joshu Hoden Kaiseki highlights the seasonal flavours of Gunma with dishes like the sumptuous Joshu Joyo Nabe chicken hotpot and takes place in the cosy confines of the main restaurant.
The Tejiko Nama-ko-uchi Soba Kaiseki features 100% buckwheat juwari soba, crafted from locally sourced flour and paired with a rich, three-stage dipping broth brewed from bonito, kelp and dried shiitake mushrooms.
This option is served at Soba Kappo SAI. A new addition to the property, Soba Kappo SAI marks the KAI brand’s first venue open to the public as well as to resort guests. The restaurant features an à la carte menu alongside a variety of small plates to enjoy before the main soba dishes, offering a relaxed version of kaiseki dining.
Guests can complement their meal with a curated selection of local sake, regional craft beer or natural wines for a sophisticated evening.
