An alkaline simple sulfur spring. With pH 9.67 to 9.9, it is strongly alkaline and delivers a remarkable slippery feel, placing it squarely in the Japanese beauty-water family. A faint sulfur taste and unmistakable rotten-egg note come through on entry, from dissolved hydrosulfide and thiosulfate ions. Mineralization is light at 579 mg/kg, so the body of the water stays gentle even as the sulfur character holds its own.
Good for
Skin conditions
Sulfur and acidic waters are antibacterial and keratolytic, studied for atopic dermatitis and psoriasis.
atopic skin, eczema
Circulation
Skin-absorbed CO₂ and hydrogen sulfide relax the vessel walls; carbon-dioxide springs can raise peripheral blood flow several-fold.
tired legs
Smooth skin
Bicarbonate and alkalinity gently lift dead keratin while silica hydrates, leaving skin smooth. This is the basis of the beautifying-water (bijin-no-yu 美人の湯) reputation.
dry, rough skin
Cuts
Mineral-rich chloride, sulfate and sulfur waters have a long-recorded soothing effect on minor cuts and slow-healing skin.
minor wounds
Recovery
Warmth and buoyancy lower stress markers and improve sleep; habitual bathing is linked to lower rates of depression.
fatigue, stress
Take care
Sensitive-skin caution
Strongly acidic or sulfur-rich water can sting broken, atopic-flare, or dry elderly skin. Ease in slowly and rinse off if it stings.
broken or dry skin
- 急性疾患(特に熱のある場合)
- 活動性結核
- Malignant tumor
- 重い心臓病
- 呼吸不全
- Bleeding disorders
- Severe anemia
- その他一般に病勢進行中の疾患
- 妊娠中(とくに初期と末期)
- 皮膚・粘膜の過敏な人、特に光線過敏症の人
- 下痢患者または下痢を起こしやすい患者
Full composition
The bar is each ion's share of charge (mval%) within its group; over 20% names the spring. Gases, silica and trace metals are measured by mass only.
- Sodiumsalt's cation — pairs with chloride to make the water saltyNa⁺158mgP42 national70%
- Calciumsettling and calming; can leave a white mineral bloomCa²⁺58.9mgP60 national30%
- PotassiumK⁺1.0mgP14 national0.3%
- StrontiumSr²⁺0.10mgP26 national0.0%
- AluminumAl³⁺0.0000mg0.0%
- BariumBa²⁺0.0000mg0.0%
- Iron (II)Fe²⁺0.0000mg0.0%
- Iron (III)Fe³⁺0.0000mg0.0%
- HydrogenH⁺0.0000mg0.0%
- LithiumLi⁺0.0000mg0.0%
- MagnesiumMg²⁺0.0000mg0.0%
- ManganeseMn²⁺0.0000mg0.0%
- FeTotalFe< —mg
- Chloridetable-salt anion — coats the skin and holds heat inCl⁻297mgP63 national85%
- HSiO3HSiO₃⁻23.8mgP68 national6%
- BO2BO₂⁻15.3mgP96 national3%
- Bicarbonate"soda" — softens skin, leaves it smoothHCO₃⁻14.8mgP10 national2%
- Thiosulfateoxidized sulfurS₂O₃²⁻3.7mgP91 national1%
- Hydrogen sulfideHS⁻1.4mgP74 national0.8%
- Hydrogen phosphateHPO₄²⁻1.7mgP87 national0.4%
- FluorideF⁻0.70mgP40 national0.4%
- BromideBr⁻0.80mgP54 national0.1%
- AsO2AsO₂⁻0.0000mg0.0%
- CarbonateCO₃²⁻0.0000mg0.0%
- HSO4HSO40.0000mg0.0%
- IodideI⁻0.0000mg0.0%
- HydroxideOH⁻0.0000mg0.0%
- CadmiumCd< —mg
- ChromiumCr< —mg
- CopperCu< —mg
- Mercurytoxic trace — part of the drinking-safety checkHg< —mg
- LeadPb< —mg
Measured at the source
On the certificate
- 神経痛
- Muscle pain
- Joint pain
- Frozen shoulder
- Motor paralysis
- Joint stiffness
- Bruises
- Sprains
- Chronic digestive disorders
- 冷え症
- 糖尿病
- Diabetes
- Gout
- 便秘
Evidence
- Maeda M. 温泉の医学的効果とその科学的根拠. J. Hot Spring Science 70:197–207, 2021.
- Tei C, Kihara T. Waon Therapy for Chronic Heart Failure. J. Cardiology 53(2):214–218, 2009.
- Coavoy-Sánchez SA et al. Hydrogen sulfide and dermatological diseases. Int. J. Dermatology, 2019.
- Naito Y et al. A Hot-Spring Water Improves Inflammatory Conditions in an Atopic Dermatitis Model. Biomedicines 13(11):2707, 2025.
- Akiyama H et al. Antimicrobial effects of acidic hot-spring water on S. aureus. J. Dermatological Science 24(3):193–200, 2000.
- Toriyama T et al. Carbon dioxide foot bathing on critical limb ischemia. International Angiology 21(4):367–373, 2002.
- Li H et al. Bicarbonate Ionized Water Bathing Enhances Natural Killer Cell Activity. Scientific Reports 14:51851, 2024.
- Takeda M et al. Hot spring bathing practices have a positive effect on mental health in Japan. Heliyon 9(9):e19631, 2023.
- Ministry of the Environment, Japan. 禁忌症及び入浴又は飲用上の注意事項 (2014 notice).official