Hoshi Onsen Chojukan: Japan's Historic Meiji-Era Bathhouse Experience

What Makes Hoshi Onsen Chojukan Special

Hoshi Onsen Chojukan (法師温泉 長寿館) is a ryokan that has been welcoming guests since 1875 in the mountains near Minakami, Gunma Prefecture. Its main bathhouse, annex, and main building are all designated as National Tangible Cultural Properties — a recognition that extends beyond the bath itself to the entire property.

What draws visitors here is the combination of genuine Meiji-era architecture and a hot spring that requires no pumping or heating. The water rises naturally through the stone floor of the bath, just as it has for over a century. This is not a reconstructed heritage property or a modern ryokan built in a traditional style. The wooden beams, the high windows filtering natural light, and the stone-lined pools are original.

Hoshi Onsen sits as one of the more remote Gunma onsen town destinations, surrounded by mountains and national parkland. The ryokan is the only accommodation at Hoshi Onsen — there is no onsen town, no convenience stores, and no restaurants nearby. You come here specifically for this place, and that isolation is part of the appeal.

The Bathhouse: Hoshi No Yu and the Meiji-Era Experience

Hoshi No Yu: The Main Mixed Bath

Hoshi No Yu (星の湯) is the bathhouse that appears in nearly every photograph of Chojukan. It is a large wooden hall with high ceilings and rows of windows that let in soft, diffused light. The bath is konyoku (混浴) — mixed-gender bathing — which was once common across Japan but is now increasingly rare.

The atmosphere inside Hoshi No Yu is often described as cathedral-like. The wooden structure creaks gently, steam rises from the pools, and the light shifts throughout the day. Many visitors time their baths for early morning or late evening, when the hall is quieter and the light is at its most atmospheric.

The Sulfate Spring Bubbling From the Floor

According to the Hoshi Onsen Chojukan official website, the hot spring is a naturally occurring sulfate spring (硫酸塩泉) — specifically a calcium and sodium sulfate type. The water bubbles up directly from the bath floor without excavation or mechanical pumping.

You can actually see and feel small bubbles rising through the stone floor as you sit in the pool. The water is said to be beneficial for gastrointestinal issues, sunburn recovery, and arteriosclerosis, according to Selected Onsen Ryokan. The temperature varies slightly across different spots in the bath since the spring water emerges at multiple points.

Other Bathing Options

Beyond Hoshi No Yu, the ryokan offers additional bathing facilities including gender-separated baths. If you are uncomfortable with mixed bathing, there are alternative options available. Confirm the current schedule of women-only bathing times when you make your reservation, as policies may vary by season.

Rooms, Meals, and the Ryokan Stay

Room Types and Capacity

Chojukan has 33 Japanese-style rooms, all with tatami flooring and futon bedding. There are no Western-style beds or modern hotel furnishings. The rooms reflect different eras of the ryokan's history — some are in the original Meiji-era main building, while others are in later additions.

The ryokan has hosted numerous writers and literary figures over its history, drawn by the remote mountain setting and the quality of the spring water. The atmosphere in the rooms is quiet and unhurried, with views of the surrounding forest.

Meals and Dining

Stays at Chojukan typically include dinner and breakfast, served in a traditional kaiseki style. Meals feature local mountain ingredients from Gunma Prefecture. Upon arrival, guests are welcomed with tea at the irori (囲炉裏), a traditional sunken hearth in the entrance area — a ritual that sets the tone for the stay.

Room rates are not currently published on the official website. Check booking platforms like Japanican or Booking.com for current pricing, or call directly at +81-278-66-0005.

Mixed Bathing Etiquette and Practical Tips

Konyoku mixed bathing at Hoshi No Yu follows traditional customs. Both men and women enter the bath, typically using a small towel to cover private areas. The ryokan provides yukata robes for wearing around the property, but these are not worn into the bath itself.

A few practical points for first-time visitors:

• Wash thoroughly at the shower stations before entering the bath
• Keep your small towel out of the bath water (place it on your head or the bath edge)
• Photography is likely restricted inside the historic bathhouse — ask staff before taking any photos
• The bath area can be slippery on the stone and wood surfaces; move carefully
• If mixed bathing feels uncomfortable, ask about women-only hours or use the gender-separated facilities

For a different onsen experience in the same region, Takaragawa Onsen in Minakami offers massive outdoor riverside baths — a contrasting style to Chojukan's intimate indoor bathhouse.

Getting to Hoshi Onsen from Tokyo

Hoshi Onsen is remote. Plan your transport carefully, as missing the last bus leaves very few options.

By Shinkansen and Bus

From Tokyo Station, take the JR Joetsu Shinkansen to Jomo-Kogen Station. The ride takes approximately 1 hour and 10 minutes. From Jomo-Kogen, take a bus to Sarugakyo Onsen (about 30 minutes), then transfer to the Hoshi Onsen bus (15-20 minutes).

Total journey time from Tokyo is roughly 2 to 2.5 hours, but this depends on bus connections. Check the bus schedule before you travel — services are infrequent, and the last bus departs in the early afternoon.

Segment	Duration	Notes
Tokyo → Jomo-Kogen (Shinkansen)	~70 min	JR Joetsu Shinkansen
Jomo-Kogen → Sarugakyo (Bus)	~30 min	Transfer required
Sarugakyo → Hoshi Onsen (Bus)	~15-20 min	Limited departures
Total	~2-2.5 hours	Check last bus times

By Car

Driving from Tokyo takes approximately 2.5 to 3 hours via the Kan-Etsu Expressway. Exit at Tsukiyono IC, and the ryokan is about 40 minutes from the interchange. Having a car gives you more flexibility with timing, though the mountain roads can be challenging in winter.

Tips for Planning Your Stay

• Book early: Chojukan is well-known and rooms fill up, particularly during autumn foliage season and weekends
• Bring cash: The remote location means limited access to ATMs or card payment
• Check-in is at 15:00, check-out at 10:30: Arrive in time to enjoy the afternoon light in the bathhouse
• Best seasons: Autumn for mountain foliage, summer for a cool mountain retreat. Winter is atmospheric but check road and bus conditions
• Bear awareness: The surrounding mountains are bear habitat. Stick to the ryokan grounds and follow any posted warnings
• Phone reservations: The most reliable booking method is calling directly at +81-278-66-0005. Staff speak limited English, so basic Japanese phrases or booking through English-language platforms may be easier
• Day visits: Drop-in bathing may be available for non-guests, but verify availability and hours by contacting the ryokan directly

For a broader look at Gunma's onsen culture, including Kusatsu and other destinations, see our Kusatsu Onsen overview.

Frequently Asked Questions

How much does a night at Hoshi Onsen Chojukan cost?

Rates vary by room type and season. Current 2026 pricing is not listed on the official site, so check Japanican, Booking.com, or call +81-278-66-0005 for the latest rates. Stays include dinner and breakfast.

Is the mixed bathing at Hoshi Onsen mandatory?

The main Hoshi No Yu bath is traditionally konyoku (mixed), but the ryokan also has gender-separated bathing facilities. Some mixed baths offer women-only time slots — confirm the current schedule when you book. Towel covering is permitted in the bath area.

How do I get to Hoshi Onsen from Tokyo?

Take the JR Joetsu Shinkansen from Tokyo Station to Jomo-Kogen Station (about 70 minutes), then connect via bus through Sarugakyo to Hoshi Onsen (about 50 minutes total with transfer). The full journey takes 2 to 2.5 hours. Bus service is infrequent, so check schedules carefully.

Do I need to speak Japanese to stay at Hoshi Onsen?

Staff speak limited English, but the ryokan experience is intuitive — you follow the flow of check-in, bathing, dinner, and breakfast without needing fluent conversation. Booking through English-language platforms like Japanican or Booking.com avoids phone reservations in Japanese. A few basic phrases will help but are not essential.