Kusatsu Onsen: Japan’s No. 1 Hot Spring for Water Volume
Kusatsu Onsen is a historic hot spring town boasting Japan’s largest natural water output, over 30,000 liters per minute. It has been one of Japan’s top three hot springs for centuries and is one of the most popular hot spring destinations in the country.
Since there’s an abundance of hot spring water, most Onsen Ryokans ( hotspring inns) in Kusatsu Onsen offer “gensen kakenagashi” baths, meaning the water flows directly from the source without recycling or filtering—a truly luxurious way to enjoy hot spring water. Kusatsu Onsen’s water is a strong acidic or sulfur spring, known for its unique sulfur smell. While it might be unusual for beginners, the water is said to be excellent for skin conditions and beauty.
Best Season to Visit
Kusatsu Onsen is enjoyable year-round, but the best season is summer. Even in July and August, when Tokyo or Kyoto are extremely hot, Kusatsu stays cool at an average of 18°C (64°F) due to its highland location. If you’re tired from the heat and crowds during summer sightseeing in Japan, Kusatsu Onsen is a refreshing escape.
Kusatsu Onsen Attractions
Yubatake
At the center of Kusatsu’s hot spring town, Yubatake (hot water field) controls the temperature and quality of the water. It produces 4,000 liters of hot water per minute, with steam rising dramatically. Surrounded by traditional pathways and benches, it’s a great place for strolling in yukata (casual kimono) and taking photos.
Goza no Yu Public Bath
A traditional public bath recreating the communal baths of the Edo and Meiji periods. You can rent a yukata here and enjoy a day trip to soak in the bath and explore the town afterward.
- Hours:
- April to November: 7:00–21:00 (last entry 20:30)
- December to March: 8:00–21:00 (last entry 20:30)
- Fees: Adults ¥800, Children (ages 3–12) ¥400
- Yukata Rental: ¥2,500 (3 hours)
- Address: Kusatsu 421, Kusatsu Town, Gunma Prefecture Japan 377-1711
Netsu no Yu (Hot Spring Rakugo)
Famous for the yumomi (water stirring) show, where performers use long wooden boards to cool down the hot spring water while singing local songs. You can also try yumomi yourself during certain hours.
- Show Times: 9:30, 10:00, 10:30, 15:30, 16:00, 16:30
- Fees: Adults ¥700, Children ¥350
- Location: Next to Yubatake
Sainokawara Park
Located on the west side of Kusatsu Onsen town, this park is filled with steaming hot springs and streams flowing from the source. Historically called “Hell Valley,” it was once feared as a place where demons lived.
At the park’s far end is the Sainokawara Open-Air Bath, a large outdoor bath set in the forest. On Fridays from 17:30 to 20:00, the men’s bath becomes mixed-gender, so be aware. The nighttime lighting is also popular.
- Hours:
- April to November: 7:00–20:00
- December to March: 9:00–20:00 (last entry 19:30)
- Address: Kusatsu Town, Gunma Prefecture Japan 377-1711
- https://onsen-kusatsu.com/sainokawara/
Kusatsu Onsen’s Hot Spring Properties
Kusatsu Onsen’s hot spring water is classified as strongly acidic (pH 2.0) or sulfur spring. It is said to have antibacterial effects and benefits for skin diseases, diabetes, nerve pain, and beauty.
Stay in Kusatsu Onsen
Yuyado Tokinoniwa
This ryokan offers private outdoor baths in every room with water directly from the source. Guests can also enjoy 23 shared baths, from scenic open-air baths to saunas and rock baths. Rooms feature traditional Japanese interiors with futon bedding or beds.
- Address: Kusatsu Shirane 464-214, Kusatsu Town, Gunma Prefecture Japan 377-1711
- https://dormy-hotels.com/resort/hotels/tokinoniwa/
Naraya
Located near Yubatake, this ryokan uses water from the historic Shirahae Source, discovered by samurai leader Minamoto no Yoritomo in 1193. Established in 1877, Naraya features luxurious Japanese-modern interiors and all rooms are equipped with beds. Perfect for those who value design and tradition.
- Address: Kusatsu 396, Kusatsu Town, Gunma Prefecture Japan 377-1711
- https://www.kusatsu-naraya.co.jp/
Kusatsu Onsen: “Tabearuki” (Food Strolling)
“Tabearuki” is a Japanese word that means eating while walking. In Japan, eating while walking in everyday settings is considered bad manners. However, in tourist areas like onsen (hot spring) towns, it is perfectly acceptable. Kusatsu Onsen’s charming streets are home to many delicious “tabearuki” delights to enjoy.
Yamabiko Onsen Manju’s Fried Manju
Located right in front of Yubatake, this manju shop is a must-visit. Manju is a traditional Japanese sweet, and the sesame-flavored fried manju here is especially popular. How about enjoying a freshly warm manju after soaking in the onsen? As this is a well-loved shop, you might find a line of eager customers.
Yamabiko Onsen Manju
Address: 118-2 Kusatsu, Kusatsu-machi, Agatsuma-gun, Gunma Prefecture, 377-1711
Tama-ya Shoten
Also located in front of Yubatake, this shop specializes in dango (rice dumplings) and is a liquor store offering local sake and beer. They sell charcoal-grilled dango right outside the shop. The savory soy sauce flavor is a favorite and pairs perfectly with beer.
Tama-ya Shoten
Address: 377-1 Kusatsu, Kusatsu-machi, Agatsuma-gun, Gunma Prefecture, 377-1711
Okaki-dokoro Terakoya Honpo Kusatsu Branch
Okaki is a traditional Japanese snack made from rice, seasoned with soy sauce or salt. At Terakoya Honpo, you can enjoy freshly grilled, handmade okaki. You can eat it while strolling or relax inside the shop and enjoy it seated.
Okaki-dokoro Terakoya Honpo Kusatsu Branch
Address: 507 Kusatsu, Kusatsu-machi, Agatsuma-gun, Gunma Prefecture, 377-1711
Access to Kusatsu Onsen from Tokyo
- Hokuriku Shinkansen: Tokyo Station → Karuizawa Station (approx. 70 minutes)
- Bus: Karuizawa Station → Kusatsu Station (approx. 80 minutes)
More access information here
https://www.kusatsu-onsen.ne.jp/access/train.php
