Kyushu > Kumamoto > Kurokawa Onsen
Hot spring inn with 100% natural free-flowing hot spring water, offering a wide selection of open-air, private, and in-room open-air baths.
Fumoto Ryokan
ふもと旅館
Kawabata-dori, Kurokawa Onsen, Minami-Oguni machi, Aso-gun, Kumamoto Prefecture, 869-2402, JAPAN
Phone：+81-(0)967-44-0918
Spring Quality
Sodium, Calcium –
Hydrogen carbonate / Sulfate / Chloride springs
ナトリウム・カルシウム―炭酸水素塩・硫酸塩・塩化物泉
(Hypotonic, Neutral, High temperature spring)
Excellent 100% natural free-flowing hot spring
with multiple properties —
for beautiful skin, hydration, warmth, and healing
Hot springs are believed to form when rainwater or snowmelt seeps underground, or when ancient seawater becomes trapped deep within the earth. Heated by magma or the earthʼs internal heat, this water dissolves minerals from underground rocks and slowly rises to the surface over years—or even tens of thousands of years.
Onsen Components
160.9 mg/kg
52.96mval%
■ Helps improve dry skin through its moisturizing effect
■ Relieves muscle tension and alleviates pain
■ Promotes blood circulation, helping to reduce sensitivity to cold
■ Boosts metabolism and supports detoxification
54.0 mg/kg
20.39mval%
■ Supports the formation and regeneration of the skin barrier
■ Helps soothe pain and inflammation
■ Regulates the contraction and dilation of blood vessels
■ Strengthens the skin’s barrier function
288.8 mg/kg
37.01mval%
■ Helps remove old keratin and excess sebum for smoother skin
■ Leaves the skin feeling fresh and refreshed after bathing
■ Washes away impurities, keeping the skin clean
■ Helps improve circulation by dilating blood vessels
■ The main component of Hydrogen carbonate springs, known as one of the “Hot springs for beautiful skin”
197.2 mg/kg
32.10mval%
■ Dilates blood vessels and promotes circulation to the extremities
■ The warming effect from increased blood flow helps regulate the autonomic nervous system
■ Promotes skin metabolism, improving firmness and elasticity
■ Supports recovery from skin issues such as dry skin and minor cuts
■ The main component of Sulfate springs, known as one of the “Hot springs for beautiful skin”
138.7mg/kg
30.59mval%
■ Salt’s bactericidal effect helps treat minor cuts and wounds
■ Salt helps block sweat glands, enhancing heat retention
■ Improved heat retention contributes to balancing the autonomic nervous system
■ A salt coating helps promote moisture retention
397mg/kg
Exceeds the hot spring standard value of 340 mg/kg
■■ Acts like a natural soap, emulsifying dead skin cells and sebum for gentle cleansing
■■ Leaves the skin smooth and well-hydrated after bathing
■■ Provides a refreshing, clean feeling after bathing
■■ A cleansing-type onsen known as “Hot springs for beautiful skin”
This component is formed by the combination of the cation ■Sodium ions (160.9 mg/kg, 7.00 mval, 52.96 mval%) and the anion ■Hydrogen carbonate ions (288.8 mg/kg, 4.73 mval, 37.01 mval%). When present at 340 mg/kg or higher, it qualifies as a hot spring component. Commonly known as baking soda, it emulsifies sebum (breaking oils into fine particles so they mix with water), making it easier to wash away. This process softens dead skin cells and leaves the skin smooth and refined. It is a key component that characterizes “Hot springs for beautiful skin”.
*The bars for Metasilicic acid 50 mg/kg and Metaboric acid 5 mg/kg represent the qualification criteria for hot springs. The number of bars indicates values such as “more than XX times the hot spring standard” or “about XX times the hot spring standard”.
Metasilicic Acid 251.4 mg/kg
■ Natural moisturizing component
■ More than 5 times the hot spring standard (50 mg/kg)
Metaboric Acid 9.7 mg/kg
■ Helps keep the skin clean
■ About 2 times the hot spring standard (5 mg/kg)
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Total Dissolved Substances
(excluding gaseous)
1,180 mg/kg
8-11 times more components than commercial bath additives!
Hydrogen Ion
Concentration
pH 6.4
Neutral
with the skin’s natural pH
Spring Temperature
60.5 ℃
Maintained at a comfortable temperature by adjusting the water flow
Color of water /
Smell of water
Colorless to Pale green
Faint hydrogen sulfide odor
Hot Spring Flow Rate
100~150 L/min
(Private source / Mechanically pumped)
Hot Spring Water Flow per Person (Spring Discharge Rate / Maximum Guest Capacity)
→ 100–150 L ÷50 guests ＝ 2-3L /min per guest
*Note: For 100% free-flowing hot spring water (gensen kakenagashi), a minimum flow rate of 1L/min per bather is generally regarded as a guideline.
Status of Hot Spring Utilization
| Water added | Heated | Disinfected | Circulated | Bath additives |
|---|---|---|---|---|
| No | No | No | No | No |
*All baths are supplied with 100% natural free-flowing hot spring water
Private Bath “Tachi-yu”
It is the largest of the private baths. The depth increases as you move from the front to the back, reaching a maximum depth of 150 centimeters, and you can stretch your legs by holding onto the wooden pillar in the center. Stretching your arms and legs to the fullest in a natural, comfortable posture puts no strain on your back or knees.
Skin Feeling Gauge
Ideal for:
People interested in skin‑beautifying effects
People who enjoy a refreshing post-bath feeling
People looking to improve skin firmness and radiance
People with minor cuts
People sensitive to cold
People with dry skin
People looking to relax and relieve stress
Indications by Spring Quality
(for bathing)
Cuts
Peripheral circulatory disturbance
Sensitivity to cold
Depression
Dry skin
General Indications (for bathing)
Chronic pains or stiffness of muscles or joints (chronic phase of rheumatoid arthritis, osteoarthritis, lower back pains, nerve pains, frozen shoulder, bruises, sprains, etc.), Muscle stiffness in motor paralysis, Sensitivity to cold, Peripheral circulatory disturbance, Gastrointestinal hypofunction (slow digestion, intestinal gas formation, etc.) Mild hypertension, Impaired glucose tolerance (diabetes), Mild hypercholesterolemia, Mild asthma or Emphysema, Hemorrhoidal pains, Autonomic instability, Various symptoms from stress (sleep disorders, depression, etc.), Restorative phase from illness, Recovery from fatigue, Health promotions
General Contraindications (for bathing)
Active stage of diseases (especially when fever is accompanied), Active tuberculosis, Advanced
malignant tumor or the case of significant debility involving severe anemia, Severe cardiac or lung
diseases involving suffocation feelings with a little movement, Severe kidney diseases involving
edema, Gastrointestinal bleeding, When bleeding is visible, Acute exacerbation stage of chronic
diseases
*There are no general indications or contraindications for drinking.
Onsen Power Chart
Open-air bath “Momiji-no-Yu”
Bathing while listening to the murmuring of the Tanohara River flowing below the open-air bath provides a strong therapeutic effect of a change in environment.
Keywords of this Onsen
Cuts・・・① cleanses the wound ② promotes tissue regeneration, and ③contributes to disinfection.
Peripheral circulatory disturbance・・・① and ② dilate blood vessels to promote blood flow, while ③ sustains the warming effect
Sensitivity to cold・・・① conditions the skin for better heat penetration ② boosts circulation to warm the body from within, and ③locks in warmth from the outside with a protective salt film.
Dry skin・・・① exfoliates dead skin cells to smooth the skin, ② and ④ provide rich hydration, ③ maintains moisturizing effects with a
salt film.
Depression・・・② improves circulation to balance the autonomic nervous system, while ③ promotes parasympathetic activity through lasting warmth
to relieve mental tension.
Private bath “Ichi-no-Yu”
The bathtub is constructed of stone and stands on a slope, providing an excellent view. It is interesting to note that the thriving trees provide just the right amount of shade.
Onsen Classification
️Hot springs are classified not only by their spring quality, but also by three additional factors: osmotic pressure, hydrogen ion concentration (pH level), and spring temperature.
Osmotic Pressure
(Hypotonic, Weakly alkaline, High temperature spring)
In hot spring classification, “osmotic pressure” refers to comparing the concentration of dissolved components in the spring water (mainly salts) with that of human body fluids (such as blood and intracellular fluid). Based on this comparison, springs are categorized as hypotonic, isotonic, or hypertonic. The difference in concentration serves as an indicator of how easily water moves between the hot spring water and body fluids.
Total Dissolved Substances
1,180 mg/kg
Classified as a Hypotonic spring
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Isotonic It has the same osmotic pressure as human body fluids. This is equivalent to a saline solution made by dissolving 8.8 g of salt in 1 liter of water. Because its concentration is close to that of body fluids, there is minimal movement of water and minerals due to osmotic pressure, making it the least stimulating and placing the least burden on the body. |
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Hypertonic Water is more likely to be drawn out of the body, while hot spring minerals are more readily absorbed, allowing for stronger therapeutic effects. However, it can also cause “yu-atari” (bath fatigue) more easily and may be more physically demanding. It is generally considered a “strong” or highly concentrated hot spring. |
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Hydrogen Ion Concentration
(Hypotonic, Neutral, High temperature spring)
In the hot spring analysis report, the section titled “Examination and test results at gushing location” includes the listed pH value. Chemically, a pH of 7.0 is considered neutral; values below this are acidic, and values above it are alkaline. According to the “Guidelines for the Mineral Spring Analysis Methods”, the chemical nature of a mineral spring is classified based on its pH value at the time of emergence, as shown in the table below.
pH 6.4
Classified as Neutral
Spring Temperature
(Hypotonic, Neutral, High temperature spring)
60.5℃
Classified as High temperature spring
Under the “Hot Springs Act”, water that contains one or more designated substances at or above the legally specified levels and has a source temperature of 25°C or higher is classified as a “hot spring”. If the temperature is below 25°C, it is labeled a “cold mineral spring”. Furthermore, as noted above, hot springs are classified by source temperature as high-temperature spring, hot spring, or low-temperature spring.
Private bath “Go-no-Yu”
The private baths are full of the atmosphere of the outdoors. Although not as large as the standing baths, small groups can enjoy a relaxing soak in the baths. Of course, the source of the water is free-flowing.
Facility Data
| Founded in | 1955 (Showa 30) |
|---|---|
| Check in | 3:00 PM |
| Check out | 10:00 AM |
| Location | Hot spring town |
| Rooms | Total 14 rooms (11 Japanese-style rooms, 2 Japanese-Western rooms, 1 Western-style room) |
| Capacity | 50 people |
| Parking | 20 car |
| Facilities | Banquet hall, Shop |
| Internet | Wi-Fi access in all areas |
| Barrier-free | Not supported |
| Bidet toilet | Equipped |
Keywords for this inn
| 100% pure natural hot spring water |
| Variety of private baths for a relaxing onsen-hopping experience within the facility |
| Conveniently located on the main street of Kurokawa’s hot spring town |
| Reasonably priced accommodations for a comfortable and casual stay |
| Premium-quality meats and refined cuisine, also popular among female guests |
Hot Spring (Onsen) Report
| Kurokawa Onsen in Kumamoto Prefecture is now playing a textbook role for all hot spring areas in Japan. Although it is a small hot spring resort located in the mountains, the individuality of each hot spring area is not compromised, and yet the overall impression of the hot spring area is one of uniformity. As a finishing touch, Kurokawa Onsen sold “Onsen hopping pass” that allowed visitors to bathe in three baths for the purchase of one bill, and led visitors to tour the entire hot spring area while wearing yukata,... Read more → |
Transportation Access
| By bus | ○From Fukuoka: Express buses are available via Hakata Station, Tenjin Station, and Fukuoka Airport (Nishitetsu Express Bus) ○From Kumamoto: Highway buses available via Kumamoto Station, Aso Kumamoto Airport, and Aso Station (Trans Kyushu Bus) ※For Trans Kyushu Bus, there are two types of buses: one includes sightseeing in Aso and the other does not. Also available from Beppu area. ※Sanko Bus is also available from Kumamoto area. Nishitetsu Express Buses are available for Hita Station (many services, transfer at Hita Station) and for Tsuetate Onsen (few services). |
|---|---|
| Shuttle bus | None |
| By car | Exit at the Hita Interchange or Yufuin Interchange on the Oita Expressway or at the Kumamoto Interchange on the Kyushu Expressway. |
| Address | Kumamoto, Kyushu／Kurokawa Onsen／FUMOTO RYOKAN Kawabata-dori, Kurokawa Onsen, Minami-Oguni machi, Aso-gun, Kumamoto Prefecture, 869-2402, JAPAN TEL:+81-(0)967-44-0918 |