A Hot Spring Associated with Minamoto no Yoritomo
According to local tradition, Kawarayu Onsen was discovered in 1193 by Minamoto no Yoritomo, the founder of the Kamakura shogunate.
The story says that Yoritomo noticed steam rising from the ground while he was hunting in the area and discovered the hot spring.
Inside Oyu, visitors can see the “Sasa Rindō” crest, a traditional emblem associated with the Minamoto clan. The crest serves as a reminder of the area’s long historical connection with medieval Japan.
Whether experienced as history or local legend, the Yoritomo story adds a distinctive atmosphere to a visit to Kawarayu Onsen.
A Gentle Hot Spring Known as the “Bath for the Joints”
The spring at Oyu is classified as a sulfur-containing calcium-sodium chloride-sulfate spring. The water is clear, with a subtle sulfur aroma, and has a comparatively gentle character.
Kawarayu Onsen has traditionally been known as a place where people came to warm themselves and relax. In particular, the spring became associated with relief from joint discomfort and was popularly referred to as the “Bath for the Joints.”
These traditional associations reflect the historical culture of toji, or extended hot spring stays, rather than modern medical treatment. Visitors should enjoy the spring as a bathing experience and follow normal hot spring safety practices.
The Traditional “Finishing Bath” After Kusatsu Onsen
Kawarayu Onsen has also traditionally been regarded as a “finishing bath” after Kusatsu Onsen.
Kusatsu Onsen is famous for its strongly acidic hot spring water, while Kawarayu is known for its comparatively milder water. Travelers making a traditional hot spring journey through the region would sometimes visit Kawarayu after bathing in Kusatsu.
After bathing, taking a gentle walk through the surrounding hot spring town is another enjoyable way to experience the area. The combination of bathing and strolling allows visitors to appreciate both the hot spring culture and the mountain scenery.
Indoor and Open-Air Baths with Lake Views
Enjoy the Scenery from the Open-Air Bath
Oyu has separate indoor baths for men and women as well as an open-air bath where visitors can enjoy the surrounding landscape.
From the outdoor bath, views extend toward Lake Yamba Agatsuma and the mountains surrounding the reservoir.
Each season creates a different atmosphere. Spring brings fresh greenery, summer offers deep green forests, autumn adds brilliant foliage, and winter brings crisp air and snow-covered scenery.
The appearance of the lake and sky also changes according to the time of day, allowing the same bath to offer a different view on every visit.
“Stroll Through the Hot Spring Town While Enjoying the Scenery”
The concept behind the new Kawarayu Onsen district is “strolling through the hot spring town while enjoying the scenery.”
Two public parking areas have been provided, allowing visitors to leave their cars and explore the town on foot.
The walking routes offer views of the surrounding mountains, expansive skies, bridges, and Lake Yamba Agatsuma. Rather than simply visiting a bathhouse and leaving, travelers are encouraged to experience the entire hot spring neighborhood at a leisurely pace.
For visitors accustomed to Japan’s traditional hot spring culture, this combination of bathing and strolling provides a pleasant way to experience the atmosphere of a mountain onsen town.
Yukake Festival — A Spectacular Winter Hot Spring Tradition
The Legend Behind the Festival
Every year on January 20 at 5:00 a.m., the area in front of Oyu becomes the setting for the famous Yukake Festival, one of Kawarayu’s most distinctive traditional events.
The festival is connected with a local legend dating back several centuries. According to the story, the hot spring suddenly began to dry up. Villagers noticed a smell resembling cooked eggs and interpreted it as a sign from the hot spring itself.
They reportedly offered a chicken as a sacrifice and prayed for the return of the spring. When the hot water began to flow again, the villagers celebrated by shouting that the hot water had returned. This tradition is said to have developed into the custom of throwing hot spring water at one another.
A Dramatic Midwinter Celebration
In the freezing early-morning air, young local men wearing traditional fundoshi loincloths throw hot spring water over one another.
The spectacular scene expresses gratitude for the hot spring and symbolizes wishes for its continued abundance and the renewal of the community.
Even after Kawarayu Onsen was relocated to its new site, the Yukake Festival continued as an important local tradition.
For visitors, the festival offers a rare glimpse into the living traditions of a Japanese mountain hot spring community.
Access and Facilities
Getting There
By car: Approximately 60 minutes from the Shibukawa-Ikaho Interchange on the Kan-Etsu Expressway.
By train: Approximately a 15-minute walk from Kawarayu-Onsen Station on the JR Agatsuma Line.
By local bus: Approximately 3 minutes from Kawarayu-Onsen Station on the Yamba Gururin sightseeing loop bus.
Parking
Kawarayu Osawa Parking Area: 35 standard spaces, 2 priority spaces, and 4 spaces for medium-sized buses.
Uchikoshi-zawa Parking Area: 30 standard spaces, 2 priority spaces, and 5 spaces for medium-sized buses.
Regular Closures
Oyu is closed from January 1 to 3, on January 20, and on the third Thursday of each month.
A Historic Onsen Reborn in the Yamba Landscape
Kawarayu Onsen Oyu brings together centuries of history, mountain scenery, hot spring culture, and local traditions.
The story of Minamoto no Yoritomo, the tradition of Kawarayu as a finishing bath after Kusatsu, the open-air bath overlooking Lake Yamba Agatsuma, and the spectacular Yukake Festival all contribute to the character of this historic hot spring.
The relocation associated with the Yamba Dam project created a new chapter in the history of Kawarayu Onsen. Today, Oyu stands as a place where the memories of the old hot spring town meet the new landscape surrounding Lake Yamba Agatsuma.
For travelers exploring Naganohara and the Yamba Dam area, Kawarayu Onsen Oyu is an ideal place to experience both the natural beauty and the living cultural traditions of Gunma’s historic hot spring country.