Uwanari Gensen

Analysis Verified
妬泉源
The Legendary Spring of Envy

Among Arima's many "Kinsen" gold springs, the Uwanari Gensen possesses a uniquely dramatic legend. Its name, meaning "Jealousy Spring," originates from a tale where the water would boil with envy whenever a beautiful woman passed by. The current source was drilled behind the original legendary well after it ran dry, and its waters are now distributed throughout the Arima hot spring district via the Gosho source and others. This hypertonic spring, extremely rich in iron and salt, warms the body to its core, with a restorative warmth that lingers long after bathing. It is the perfect bath for a day when you wish to soothe both body and soul while reflecting on history and legend.

AI Generated
This source matches 2 spring types· Tap to switch
SPRING TYPE
Iron Spring

These springs are a distinctive cloudy reddish-brown color with an iron rust-like aroma. Due to its high iron content, drinking the hot spring water can be effective for iron-deficiency anemia.

See features & indications
Drinking indications
Iron-deficiency anemia

※ Only at facilities permitted to serve drinking water. 200–500 mL/day recommended.

Definition :Total iron(II) and iron(III) ions of 20 mg/kg or more.
Source: 環境省「あんしん・あんぜんな温泉利用のいろは」(監修:日本温泉気候物理医学会)Read full article
PH VALUE
6.7
Neutral
Acidic ← 07 Neutral14 → Alkaline
Neutral (pH 6-7.5) per Japan Ministry of Environment classification. The pH range gentlest on the skin, suitable for long bathing.
TEMPERATURE
100.5
Very Hot Spring
Near boiling, extremely hot. Requires substantial cooling or dilution.
KEY MINERALS

The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).

Metaboric acidSee detail
272 mg/kg

Undissociated boric acid with antibacterial action that keeps the skin surface clean.

Chloride ionSee detail
21980 mg/kg

Salinity comparable to seawater. The salt film traps heat for outstanding warmth ("hot bath spring").

Sodium ionSee detail
10840 mg/kg

Salt forms a thin film on the skin, retaining heat after bathing. Helps with poor circulation.

Bromide ionSee detail
38.7 mg/kg

Gentle calming action; often found alongside chloride.

Iron(II) ionSee detail
67.0 mg/kg

An iron-rich spring whose water turns yellow-brown to red-brown when exposed to air. Strong heat retention.

CHARACTER · COMPOSITION PROFILE
1234StimulationBactericidalSkin BeautyHeat RetentionRelaxation

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.

USAGE
Usage status is unknownInformation from facility postings or official sites has not been confirmed. Please check with staff on site.
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.

SENSORY TEST
Color
緑色沈澱あり、淡緑色微濁
Smell
殆ど無臭
Taste
強鹹味
EFFECTS
Spring-specific indications (bathing)
Cuts and grazesPeripheral circulatory failurePoor circulationDepressionXerodermaChronic pain or stiffness in muscles and joints (chronic phase of conditions such as rheumatoid arthritisosteoarthritislow back painneuralgiafrozen shoulderbruisessprains)muscle stiffness due to motor paralysispoor circulationgastrointestinal dysfunction (e.g.stomach sluggishnessintestinal gas)mild high blood pressureimpaired glucose tolerance (diabetes)mild dyslipidemiamild asthma or emphysemahemorrhoid painautonomic instabilitystress-related symptoms (e.g.insomniadepression)post-illness recoveryfatigue recoveryhealth promotioncuts and grazesxerodermamenstrual disordersuterine hypoplasiainfertility
General indications (bathing)
High blood pressure (mild)Rheumatoid arthritisAutonomic instabilityInsomniaChronic pain or stiffness in muscles and jointsMuscle stiffness due to motor paralysisGastrointestinal dysfunction
Contraindications
Acute illness (especially with fever)Active tuberculosisMalignant tumorsSevere heart diseaseRespiratory failureRenal failureBleeding disordersSevere anemiaAny actively progressing illnessPregnancy (especially early and late stages)(Bathing) Active stages of disease (especially with fever)active tuberculosisadvanced malignant tumors or severe anemia causing significant physical weaknesssevere heart or lung disease causing shortness of breath with slight movementsevere kidney disease with edemagastrointestinal bleedingvisible bleedingacute exacerbation of chronic illness.
BATHING TIPS
AI Generated

This is an extremely hot spring over 100°C with high salt concentration. Avoid long soaks; instead, practice "bunkatsu-yu" (split bathing) with short, repeated dips. The salt helps retain moisture, but those with sensitive skin may want to rinse off lightly with a shower afterward.

EFFECT STORY
AI Generated

With a total dissolved solids count of 37.6 g/kg, this hypertonic spring is a prime example of balneotherapy. Its abundant chloride ions (21980 mg/kg) form a thin veil on the skin, providing exceptional restorative warmth and preventing post-bath chills. It's ideal for those seeking deep warmth and may support the relief of chronic pain.

CAUTIONS
AI Generated

This is a hypertonic spring extremely rich in salt and iron. Due to its very high temperature, individuals with high blood pressure or heart conditions should bathe with caution. Avoid prolonged soaking and stay hydrated.

※ See the analysis data below for detailed contraindications

ANALYSIS DATAView all analysis fields ▼

Source Info

Source name
Uwanari Gensen
Spring type
Iron-containing Sodium Chloride strong saline Hot Spring (Hypertonic Neutral high-temperature hot spring)
Source temperature
100.5℃
pH
6.7
Flow rate
120 L/min
Flow type
掘削・自噴
Osmotic pressure
高張性

Analysis Document

Analysis date
2019-09-24
Analyst organization
公益財団法人 中央温泉研究所
Registration No.
14健地衛第1号

Cations

Sodium ion Na⁺
10840 mg/kg
Potassium ion K⁺
2045 mg/kg
Ammonium ion NH₄⁺
4.0 mg/kg
Magnesium ion Mg²⁺
13.8 mg/kg
Calcium ion Ca²⁺
1825 mg/kg
Aluminum ion Al³⁺
0.00 mg/kg
Manganese ion Mn²⁺
17.1 mg/kg
Iron(II) ion Fe²⁺
67.0 mg/kg
Total cations
14.8 mg/kg

Anions

Fluoride ion F⁻
0.30 mg/kg
Chloride ion Cl⁻
21980 mg/kg
Hydrogen sulfide ion HS⁻
0.10 mg/kg
Thiosulfate ion S₂O₃²⁻
0.00 mg/kg
Sulfate ion SO₄²⁻
29.6 mg/kg
Bicarbonate ion HCO₃⁻
298 mg/kg
Carbonate ion CO₃²⁻
0.00 mg/kg
Bromide ion Br⁻
38.7 mg/kg
Iodide ion I⁻
5.1 mg/kg
Total anions
22.4 mg/kg

Undissociated Components

Metasilicic acid H₂SiO₃
160 mg/kg
Metaboric acid HBO₂
272 mg/kg
Total undissociated
0.43 mg/kg

Dissolved Gas

Free carbon dioxide CO₂
136 mg/kg
Free hydrogen sulfide H₂S
0.20 mg/kg
Total dissolved gas
0.14 mg/kg

Totals

Total dissolved substances
37.6 mg/kg
Component total
37.7 mg/kg
Evaporation residue
38.0 mg/kg

Usage

Usage status
Unknown

Indications & Contraindications

Bathing indications
Cuts and grazes, Peripheral circulatory failure, Poor circulation, Depression, Xeroderma, Chronic pain or stiffness in muscles and joints (chronic phase of conditions such as rheumatoid arthritis, osteoarthritis, low back pain, neuralgia, frozen shoulder, bruises, sprains), muscle stiffness due to motor paralysis, poor circulation, gastrointestinal dysfunction (e.g., stomach sluggishness, intestinal gas), mild high blood pressure, impaired glucose tolerance (diabetes), mild dyslipidemia, mild asthma or emphysema, hemorrhoid pain, autonomic instability, stress-related symptoms (e.g., insomnia, depression), post-illness recovery, fatigue recovery, health promotion, cuts and grazes, xeroderma, menstrual disorders, uterine hypoplasia, infertility
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), (Bathing) Active stages of disease (especially with fever), active tuberculosis, advanced malignant tumors or severe anemia causing significant physical weakness, severe heart or lung disease causing shortness of breath with slight movement, severe kidney disease with edema, gastrointestinal bleeding, visible bleeding, acute exacerbation of chronic illness.

Drinking

Drinkability
Not drinkable
FACILITY INFO
Private bath (Kashikiri)
Available
Room with private open-air bath
Available
About tattoos and onsen
Travelers with tattoos can still bathe comfortably in a private bath (Kashikiri) or a room with a private open-air bath.
Transit
5 min walk from Arima Onsen Station (神戸電鉄有馬温泉駅) on Kobe Electric Railway. Approx. 30 min by car/train from Shin-Kobe Station (新神戸駅). Approx. 50 min by highway bus from Shin-Osaka Station (新大阪駅). 50 min by train from Kobe Airport (神戸空港).
Parking
Available. 50 spaces. Free. No reservation required.
This information may change without notice. Please contact the facility directly for accurate details.
Last updated: 6/8/2026
How Long to Stay (Toji)
Start with 2 nights / 3 days

Japan’s Ministry of the Environment notes that even a short stay refreshes you. For a full therapeutic cure, around 2–3 weeks is the guideline.

More on toji length
The descriptions, catch phrases, and translations on this page are generated by AI (Claude). pH, temperature, and component values are OCR-extracted from the official analysis report. Learn more