Shima Onsen

What to expect

Shima Onsen strings out along the Shima River in the mountains of Nakanojo, in northwest Gunma, inside Joshin’etsu Kogen National Park. The local association traces it to the 700s as a place to bathe for healing. The name is usually read as “forty thousand”, for a legendary spring said to cure forty thousand ailments. Writers and thinkers such as Fukuzawa Yukichi, Yosano Akiko and Dazai Osamu stayed here, and parts of the main street keep a Showa-era look of old shopfronts and wooden inns.

Compared with Kusatsu or Ikaho, it is quiet. There is no central steaming field and no stone staircase. You come for a slow walk up the valley, a few small public baths and a night in an inn by the river.

The association counts 42 sources. The water is sodium-calcium chloride-sulfate, and Shima has long been called one of Japan’s three famous springs for stomach complaints. Treat that as tradition.

The public baths

Day visitors have three free baths and one paid town spa. The free ones are maintained by residents and open to visitors only from 9:00 to 15:00. Each has a donation box. Nakanojo’s tourism office lists no regular closing day.

• Kawara-no-yu: by Hagi Bridge, where the Shima and Shinyu rivers meet, right by the last stop of the Shima Onsen bus. The building, walls and tubs are stone, which gives it a cave-like feel. Men’s and women’s baths are separate. A small park above it is a good place to cool off.
• Gomuso-no-yu: a wooden bathhouse in the old yuya style, rebuilt and reopened in January 2006. Local legend says this is where the spring first appeared: a retainer of Minamoto no Yorimitsu, Usui Sadamitsu, chanted sutras here all night, dreamed of a child who promised a healing spring, and woke to find hot water bubbling up. It is treated as the origin of Shima Onsen.
• Kami-no-yu: a small bath in the Yamaguchi district further down the valley, easy to miss beside the road. It has separate men’s and women’s indoor baths, each with two tubs fed straight from the source.

These are simple community baths: a changing shelf, a tub, a tap. Do not expect soap, shampoo or towels, so bring your own small towel and wash before you go in.

Shima Seiryu-no-yu is the town-run day spa on the river, with two indoor baths (Ogi-no-yu and Yabane-no-yu) and two open-air baths (Hyotan-no-yu and Oborozuki-no-yu). Prices in 2026:

Ticket	Adults	Children
2 hours	¥600	¥400
Weekday evening, after 17:00	¥600	¥400
Each extra hour (weekdays)	¥300	¥200
10-visit book	¥4,000

Private rooms cost extra. Its hours are temporarily cut to 10:00 to 17:00 (last entry 16:30) until further notice, against a normal 10:00 to 20:00, and equipment trouble can cause short-notice closures. It closes on the fourth Wednesday of most months and at year end; in late 2026 the town lists October 29 and November 25 as closed days. The spa refuses entry to anyone with a tattoo, anyone heavily drunk and anyone with an uncovered bleeding wound. Phone 0279-64-2610.

A roadside foot bath in the Yamaguchi district (Yamaguchi Kawane no Ashiyu) is listed as closed.

Sekizenkan

Sekizenkan is the inn most people picture. Nakanojo’s tourism office says its main building was built in 1691 (Genroku 4) and calls it the oldest surviving hot spring inn building in Japan. A red bridge crosses to it, and its newer wings climb the hillside behind. The town lists it as offering day bathing, but it does not publish prices or hours, so call the inn (0279-64-2101) before you go. Its website was not loading in October 2026.

Onsen etiquette

• Rinse thoroughly before getting in. The free baths have no showers.
• Bathe naked in the separate men’s and women’s baths. Towels stay out of the water.
• Keep to the 9:00 to 15:00 window. Outside it, the baths belong to residents.
• Leave a donation. The baths run on them.
• Keep it quiet. These are small rooms, often with locals in them.

Getting there

• By train: the JR limited express Kusatsu Shima runs from Ueno to Nakanojo in about 2 hours 5 minutes. Or take the Shinkansen to Takasaki (about 50 minutes from Tokyo) and the JR Agatsuma Line to Nakanojo (about 55 minutes).
• Bus from Nakanojo: the Kan-etsu Kotsu Shima Onsen line runs up the valley. Mapple gives about 40 minutes to the terminus by Kawara-no-yu and about 28 minutes to the Yamaguchi stop for Kami-no-yu. A two-day bus pass is sold online.
• Direct bus from Tokyo: the Shima Onsen-go runs from Tokyo Station Yaesu to Nakanojo Station and Shima Onsen in about 3 hours 30 minutes. Nakanojo’s tourism office also lists direct buses from Kawagoe and Haneda.
• By car: take the Kan-etsu Expressway to Shibukawa-Ikaho IC (about 15 minutes past Takasaki JCT), then Route 353 to Nakanojo (about 40 minutes), and on up the valley to Shima.

When to go

Shima is open all year. Autumn, from mid-October into November, is the busiest time, when the valley turns red and gold. Winter is quiet and cold, with snow in the upper village. Early summer is green and good for walks to Okushima Lake and the waterfalls. Weekdays are calmer everywhere, and the free baths are busiest around midday.

Where to stay nearby

The Shima Onsen Association lists member inns including Sekizenkan, Kashiwaya Ryokan, Izumiya, Toshimaya, Shima Tamura, Shima Grand Hotel and Kagen, plus a hot spring glamping site, Shima Blue. Staying overnight lets you use your inn’s baths in the evening, after the free baths close.

Ikaho Onsen, with its stone steps, is the nearest big onsen town by car. Kusatsu Onsen is further west on the Agatsuma Line side, and Minakami Onsen is to the northeast.

Nearby stops worth adding

Okushima Lake, behind a dam at the top of the valley, is the local photo spot for its vivid blue water, and you can canoe on it. The Shima River has potholes worn into the riverbed, and the area has several waterfalls, including Maya-no-taki and Oizumi-no-taki. Canyoning trips run on the river.

Safety notes

• Heat: the free baths take water straight from the source, and some tubs run hot. Test first and keep soaks short.
• Footing: stone floors and steps into the tubs get slippery.
• Hydration and alcohol: drink water, and do not bathe after drinking.
• Roads in winter: the valley road is narrow in places and can be icy. Use winter tyres from December to March.