Toyotomi Onsen (豊富温泉)

Toyotomi Onsen: Japan’s Miraculous “Oil Spa” and the Northernmost Wellness Retreat

Deep in the northern reaches of Hokkaido, on the edge of the vast Sarobetsu Plain, lies Toyotomi Onsen—a destination that feels like a discovery from another world. Established in 1926, this unique hot spring village is globally renowned for its rare “oil bath,” a natural phenomenon found in only two places on Earth. The water here contains high concentrations of natural petroleum and gas, resulting in a yellowish, murky soup with a distinct scent of gasoline and a texture that feels like a high-end cosmetic oil. Far from a typical resort experience, Toyotomi has become a “sacred site” for medical tourism, attracting visitors from across the country seeking relief from chronic skin conditions. Surrounded by the wild beauty of the Sarobetsu Wetland and the distant peak of Mt. Rishiri, it offers a meditative, slow-paced sanctuary where the raw chemistry of the earth provides life-changing healing.

Key Information

The Healing Waters: The Science of the “Miracle Oil Bath”

Toyotomi Onsen’s water quality is a byproduct of history and geology. Discovered by accident during oil drilling in 1926, the hot water gushed forth along with crude oil and methane gas. Scientifically, the water is a hypertonic saline spring rich in bicarbonate and boron. The unique “oil layer” that floats on top of the baths is primarily composed of catechins and tars, which possess powerful anti-inflammatory and antibacterial properties. When you soak, the oil adheres to the skin, acting as a natural moisturizing barrier that penetrates deep into the epidermis to soothe irritation and promote cellular regeneration. For this reason, it is designated as a “National Hot Spring Health Resort” (Kokumin Hoyo Onsenchi), with doctors often providing guidance on long-term thermal therapy for those with severe skin ailments.

Top 5 Recommended Ryokans

• Kawashima Ryokan (Design/Gourmet): A stylishly renovated inn that perfectly blends modern aesthetics with traditional “toji” hospitality. Famous for its award-winning “Yuagari Pudding” and its focus on local Sarobetsu dairy products.
• Hotel Toyotomi (Resort/Family): The largest hotel in the village, offering spacious Western and Japanese rooms. It is the only facility in the area with its own large-scale sauna and a wide range of buffet dining options.
• New Onsenkaku Hotel (Heritage/Value): A classic establishment that maintains the atmosphere of a traditional mountain lodge. It features 100% free-flowing mineral baths and is highly regarded for its hearty home-style meals.
• Sarobetsu Hotel (Authentic/Toji): A welcoming, modest facility popular with long-stay guests who are there primarily for skin treatments. It offers a quiet environment and specialized guidance for first-time oil bathers.
• Hostel Toyotomi (Budget/Solo): A high-quality budget option that allows travelers to access the thermal healing of the village while maintaining independence and connecting with other nature lovers.

Must-Visit Public Baths (Soto-yu)

The Toyotomi Onsen Fureai Center is the spiritual and social heart of the town. This municipal facility is divided into two areas: the “General Bath,” designed for tourists and those seeking a lighter oil concentration, and the “Therapeutic Bath” (Toji-yu), where the oil concentration is at its peak for those undergoing skin treatment. Entry is approximately 510 yen. A standout experience here is the manual addition of fresh crude oil to the men’s bath every morning—a process that must be seen to appreciate the raw nature of the springs. There is also a spacious resting hall where visitors can enjoy local milk after their soak.

Walking Guide & Scenic Spots

Nature is the main attraction outside the tubs. Visit the Sarobetsu Wetland Center, just a 15-minute drive away. In summer, follow the boardwalks through one of Japan’s largest marshes to see millions of daylilies and other alpine flora. On clear days, the view of Mount Rishiri (the “Rishiri Fuji”) rising out of the sea is spectacular. For a panoramic view of the entire plain and the Okhotsk Sea, drive up to the Toyotomi Town Observatory at sunset. In winter, the area is a silent kingdom of snow, perfect for seeing “Sun Pillars” and other rare northern light phenomena.

Local Gastronomy & Souvenirs

Toyotomi Town is a dairy powerhouse. You must try Sarobetsu Milk, which is incredibly rich and used by top cafes across Japan. The Yuagari Pudding at Kawashima Ryokan comes in several flavors and is the village’s most famous souvenir. For dinner, local specialties include Sarobetsu Genghis Khan (mutton) and handmade ham and sausages flavored with mountain garlic. At the Yunomori Pokke community center, you can enjoy pizza made with local cheese and buy hand-crafted “oil bath salts” to recreate the therapeutic soak at home.

Cultural & Historical Context

Before the oil exploration in the 1920s, the Ainu utilized the natural springs of the area for purification and healing. The town’s name itself, “Toyotomi,” means “abundance,” reflecting the richness of the soil and the thermal sources. In 2026, the village will celebrate its 100th anniversary of discovery. This history of transition from a failed oil field to a world-class healing resort is documented at the Toyotomi Town History Museum, where you can see the original drilling equipment and early photos of the pioneers who first bathed in the oily sludge.

Practical Travel Tips

The Smell: Be prepared that the petroleum scent is strong and will linger on your skin and towel for a few days—most visitors grow to find it relaxing. Jewelry: Remove all silver jewelry before entering, as the sulfur and oil will darken it instantly. Winter Travel: This is one of the windiest and snowiest parts of Hokkaido; if visiting between December and March, check the road status for the “Sarobetsu Line” frequently. Cash: While hotels accept cards, the Fureai Center and local eateries often only take Japanese Yen.

2025-2026 Latest Updates

Starting in March 2025, the “Welcome Suica” update allows long-stay visitors to use their cards for 180 days, making it easier for repeat “toji” guests to pay for local transport and small purchases. Additionally, the Toyotomi 100th Anniversary Thermal Fair is planned for early 2026, featuring special “deep oil” events and collaborative local product markets at the Fureai Center.

Safety & Manners

Toyotomi’s water can be extremely slippery due to the oil content—always use the handrails when entering and exiting the tub. In the “Toji” bath area, remember that many guests are there for serious medical healing; maintain a quiet and respectful volume. Finally, respect the surrounding Sarobetsu National Park by staying on marked boardwalks and not approaching wild animals like red foxes, which are common in the area.