Umanoyu Gensen
Analysis VerifiedNestled in Noboribetsu Onsen, famously called the "Department Store of Hot Springs" and rooted in the Ainu "Nupur-pet" (deeply colored river), the historic "Uma no Yu" source has flowed since Taisho 6 (1917). Its faint sulfur aroma gently unwinds the mind and body. The waters, softly enveloping the skin, warm the body to its core, providing restorative warmth that lingers. Overlooking a beautiful Japanese garden, this tranquil spring offers deep relaxation, a serene escape from daily commotion.
The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).
The source of the distinctive sulfur smell. Dilates blood vessels via skin and inhalation to strongly boost circulation.
A trace component with gentle antibacterial and anti-inflammatory action.
A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.
- Sulfur19.3 mg/kg
- Feel
- Smells like boiled eggs; the water may turn milky white or blue-green.
- Said to
- Said to be strongly antibacterial and to promote circulation. Bathing indications include atopic dermatitis and chronic eczema.
- Note
- With sensitive skin, rinse with fresh water after bathing. Remove silver jewelry—it tarnishes.
- Chloride (salt)259 mg/kg
- Feel
- Tastes salty; the warmth lasts after you get out.
- Said to
- Salt is said to form a film on the skin that keeps in heat and moisture. Bathing indications include cuts, poor circulation and dry skin.
- Note
- May sting cuts. Strong salty water can tire you—avoid long soaks.
- Bicarbonate (baking soda)274 mg/kg
- Feel
- Your skin feels smooth and silky.
- Said to
- Said to remove old skin cells and excess sebum. Bathing indications include cuts, poor circulation and dry skin.
- Note
- It can leave skin dry—moisturize after bathing.
- Metasilicic acid236 mg/kg
- Feel
- Your skin may feel smoother.
- Said to
- 50 mg/kg or more is said to mark a “skin-beautifying spring”; it is also used in skincare.
- Note
- The “skin-beautifying” label is a common rule of thumb, not a legal standard.
- Source temperature62.3℃
- Feel
- The source is 42°C or hotter; the bath may be on the hot side.
- Said to
- Heat is said to boost circulation and warm the body.
- Note
- Older people and those with high blood pressure or heart conditions should avoid baths of 42°C or more. Keep soaks short.
Effects are general descriptions based on the Ministry of the Environment’s indications by spring type, not a guarantee.
Scores are calculated from mineral analysis data based on the Mineral Spring Analysis Guidelines (Ministry of Environment, Japan). They are unrelated to facility atmosphere or service quality.
▸Note
The temperature, pH and component values shown here are based on the hot spring analysis (source). Actual values in the bath may differ depending on heating, dilution, recycling and filtration. Please check current usage status at the facility.
This is an authentic hydrogen-sulfide-rich sulfur spring with a pungent odor. Though source temperature necessitates occasional dilution for comfort, all baths maintain free-flowing circulation. To prevent thermal shock, begin with 3–10 minute soaks, pausing frequently for rest and hydration between visits.
Rich in metasilicic acid (236.4 mg/kg) at pH 6.4, this spring excels at deep moisturizing, making it ideal for those battling atopic dermatitis and chronic eczema. Its core-warming properties relieve peripheral circulation disorders and chronic chills while nurturing fatigue recovery and revitalization.
Avoid bathing during active illness or high fever, or if suffering from serious cardiac, pulmonary, or renal conditions. This spring is not potable.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- Umanoyu Gensen
- Spring type
- 含硫黄－ナトリウム・カルシウム－塩化物・炭酸水素塩温泉（硫化水素型）
- Old spring type name
- 含土類－食塩硫化水素泉
- Source temperature
- 62.3℃
- pH
- 6.4
- Flow type
- 自然湧出
- Osmotic pressure
- 低張性
Analysis Document
- Analysis date
- 2019-03-29
- Analyst organization
- 株式会社 環境総合科学
- Registration No.
- 北海道第4号
Cations
- Sodium ion Na⁺
- 180 mg/kg
- Potassium ion K⁺
- 26.1 mg/kg
- Ammonium ion NH₄⁺
- 1.6 mg/kg
- Magnesium ion Mg²⁺
- 10.6 mg/kg
- Calcium ion Ca²⁺
- 95.7 mg/kg
- Manganese ion Mn²⁺
- 0.90 mg/kg
- Iron(II) ion Fe²⁺
- 0.30 mg/kg
- Lead ion Pb²⁺
- 0.00 mg/kg
- Copper ion Cu²⁺
- 0.00 mg/kg
- Cadmium ion Cd²⁺
- 0.00 mg/kg
- Total cations
- 315 mg/kg
Anions
- Fluoride ion F⁻
- 0.60 mg/kg
- Chloride ion Cl⁻
- 259 mg/kg
- Hydrogen sulfide ion HS⁻
- 3.3 mg/kg
- Thiosulfate ion S₂O₃²⁻
- 0.30 mg/kg
- Sulfate ion SO₄²⁻
- 113 mg/kg
- Bicarbonate ion HCO₃⁻
- 274 mg/kg
- Carbonate ion CO₃²⁻
- 0.10 mg/kg
- Hydrogen phosphate HPO₄²⁻
- 0.20 mg/kg
- Total anions
- 650 mg/kg
Undissociated Components
- Metasilicic acid H₂SiO₃
- 236 mg/kg
- Metaboric acid HBO₂
- 28.0 mg/kg
- Total undissociated
- 264 mg/kg
Dissolved Gas
- Free carbon dioxide CO₂
- 24.0 mg/kg
- Free hydrogen sulfide H₂S
- 16.9 mg/kg
- Total dissolved gas
- 40.9 mg/kg
Trace Components
- Radon Rn
- 0.78 mE/kg
Totals
- Total dissolved substances
- 1230 mg/kg
- Component total
- 1271 mg/kg
- Evaporation residue
- 1060 mg/kg
Usage
- Heating
- No
- Dilution
- Yes
- Recycle / Filter
- No
- Additives
- No
- Disinfection
- No
Indications & Contraindications
- Bathing indications
- Atopic dermatitis, Plaque psoriasis, Chronic eczema, Epidermal suppuration, Cuts and grazes, Peripheral circulatory failure, Poor circulation, Depression, Xeroderma
- General indications
- High blood pressure (mild), Rheumatoid arthritis, Autonomic instability, Insomnia, Chronic pain or stiffness in muscles and joints, Muscle stiffness due to motor paralysis, Gastrointestinal dysfunction
- Contraindications
- Acute illness (especially with fever), Active tuberculosis, Malignant tumors, Severe heart disease, Respiratory failure, Renal failure, Bleeding disorders, Severe anemia, Any actively progressing illness, Pregnancy (especially early and late stages), Severe chronic dermatitis (sulphur springs)
Drinking
- Drinkability
- Not drinkable
