Ekinariya Ryokan

This inn draws from the Shirahata source and the Yubatake source, two of the representative spring sources of Kusatsu Onsen. Both spring qualities are "Acidic, Sulfur containing ― Aluminum ― Sulfate/Chloride springs (Hydrogen sulfide type)".
In Japan, hot springs are classified into 10 types, of which "Acidic spring", "Sulfur spring", "Sulfate spring", and "Chloride spring", which means this spring has the characteristics of 4 different types of hot springs.

First, one of the conditions for "Acidic spring" is that 1 mg or more of hydrogen ions must be contained in 1 kg of hot spring water. The pH value (hydrogen ion concentration) of this hot spring is 2.0, which is acidic, and is often shows strong acidity.
With its extremely high antibacterial power, it is effective against atopic dermatitis, trichomonas vaginalis, and athlete's foot, and is called "Hot spring for skin diseases" because it widely removes the causes of problems on the surface of the skin.
Also, the indications by spring quality include Plaque psoriasis, Impaired glucose tolerance (diabetes), and Epidermal suppuration.
It is curious that the color of the hot spring water right after it gushes out from the source is clear and colorless, but it appears milky emerald green, as seen in the Yubatake source. In fact, the cause of this color is said to be related to a microorganism called "Ideyukogome (cyanidiophyceae)". It is a single cell that prefers the harsh environment of acidic hot water and is a type of algae, and it is said that Kusatsu hot spring area is the best breeding place for it in Japan.

Next, a "Sulfur spring" must contain at least 2 mg of total sulfur (the sum of (1) Hydrogen sulfide ion, (2) Thiosulfate ion, and (3) Free hydrogen sulfide) in 1 kg of hot spring water. There are two types of Sulfur springs: "Sulfur type", which consists mainly of (1) + (2), and "Hydrogen sulfide type", which contains more (3). Here in Kusatsu Onsen, it is a "Hydrogen sulfide type - Sulfur spring".
The color of the water is often milky white, and the indications by spring quality have much in common with "Acidic spring": Atopic dermatitis, Plaque psoriasis, Chronic eczema, Epidermal suppuration, and Peripheral circulatory disturbance.
The "Sulfur spring" has a high antibacterial effect like the "Acidic spring", and is said to be "Hot spring for skin diseases" for all skin surface problems, but it also removes excess sebum, making it a good match for people prone to acne and those with oily skin. It is also called "Hot spring for prevention of spots" because it suppresses the production of melanin, the substance that causes spots, and can be expected to have a whitening effect as well. In other words, "Sulfur spring" is a typical "Hot spring for beautiful skin".
In addition, it is sometimes called "Hot spring for phlegm" because it relieves asthma and improves the sharpness of phlegm.
One thing to keep in mind is that metal rings and necklaces must be removed when bathing, as the sulfur component can cause discoloration.
Contraindications by spring quality for bathing includes hypersensitive skin or mucous membranes, and dry skin in the elderly (※same as Acidic spring).
In other words, "Sulfur springs", like "Acidic spring", are highly stimulating springs, so the sickly, elderly, and those with weak skin should be careful and are prone to "Hot spring fatigue". Many of the best hot springs are a combination of "Acidic spring" - Hot spring for antibacterial and "Sulfur spring (Hydrogen sulfide type)" - Hot spring for beautiful skin. However, please keep in mind that the stronger the efficacy, the more stressful it is on the skin.

One of the conditions for a "Sulfate spring" is that the main component of the anion is the sulfate ion.
The indications by spring quality for bathing are Cuts, Peripheral circulatory disturbance, Sensitivity to cold, Depression, and Dry skin.
The "Hot Spring Analysis Report" shows that the cations are rich in aluminum ions, which are combined with sulfate spring water to make the former name of the spring, "Myoban-sen (Alum spring)". Its so-called convergence action, which shrinks tissues and blood vessels by denaturing proteins, tightens the skin, activates metabolism, and promotes skin revitalization. Therefore, it is effective for cuts, burns, acne, psoriasis, itching, and chronic eczema, and is therefore also called "Hot spring for cuts".
In addition, the "Sulfate spring" is highly effective for oily skin because of its ability to wash away excess oil from the skin.
Also, the sulfate ions have the effect of pumping more oxygen into the blood and rehydrating the skin, making it taut and moisturized, which is an anti-aging effect. This is why it is called "Hot spring for rejuvenation". Like sulfur spring, it is also known as a "Hot spring for beautiful skin".

Finally, the "Chloride spring" has the same five indications as the "Sulfate spring", including Cuts, Peripheral circulatory disturbance, Sensitivity to cold, Depression, and Dry skin.
The salt has antibacterial effects, so it is a typical "Hot spring for cuts".
A "Chloride spring" is also sometimes referred to as a "Hot spring for warmth". This is because the salts in the spring water adhere to the skin and form a film, which works like a pack to block the sweat glands after the bath, preventing the body temperature from dropping due to sweating. Because of the warming effect and the long-lasting warmth, Peripheral circulatory disturbance and Sensitivity to cold are recognized as indications. Although Sensitivity to cold is also an indication for other types of springs, the "Chloride spring" is considered to be particularly effective.
This hot spring pack is also effective as an indication for Dry skin because it prevents skin from drying out after the bath. And, as with "Sulfate springs", the fact that Depression is recognized as an indication by spring quality is probably due to the low-irritant character of the spring, compared to "Acidic spring" and "Sulfur spring".

The amount of "Metasilicic acid", a non-dissociated component other than cations and anions, is also noteworthy.
More than 200 mg of metasilicic acid is contained per kilogram of spring water, which is four times higher than the standard value for hot springs (50 mg/kg). Metasilicic acid is used as an ingredient in some lotions and has moisturizing effects. Hot springs with high metasilicic acid content can be called "Hot spring for beautiful skin".
Furthermore, the amount of "Metaboric acid" is also amazing. This also contains almost double the standard value (5 mg/kg) for hot springs.
It has a cleansing effect, is used in some eye drops, and is said to be effective against acne.

The quality of the hot spring water in this inn is of such a high quality that it deserves to be called a "Famous hot spring in Japan", but it is also used in a very thorough manner.
The bathhouse does not use circulation, filtration, or disinfection, but always pours "100% natural hot spring water" into the bathtub, which is then overflowed and replaced with new hot spring water. The innkeepers also adjust the amount of hot spring water poured into the bathtub from the hot water outlet, taking into account the temperature of the day, to keep the water at the proper temperature.

Kusatsu Onsen boasts the largest amount of naturally gushing hot spring water in Japan, which means that no motors are used to pump the spring water up from underground. The overflow of hot spring water from a source close to the surface of the earth means that there is little possibility of impurities entering the water. The ingredients of the hot spring are also very high, as you can see above.
We hope you will experience the blessings of nature and the gifts of the earth to your heart's content.

Kusatsu Onsen, located at the eastern foot of the active volcano Mount Kusatsu-Shirane, is known as one of Japan's most famous hot spring areas, even more than as a notable spot within Gunma Prefecture. In the Edo period (1603-1868), Kusatsu Onsen was ranked at the highest level (Ozeki) in eastern Japan in the Onsen Banzuke, which was based on the Sumo Banzuke (a ranking chart for sumo wrestlers). Dr. Bälz of Germany, who came to Japan during the Meiji period (1868-1912) and is known as the "father of modern medicine" in Japan, loved the cold climate at an altitude of 1200ⅿ and the highly acidic waters of Kusatsu Onsen, which is rare in Europe. He later studied the onsen's mineral composition and promoted the benefits of onsen therapy. Even today, Kusatsu Onsen remains Japan's most popular hot spring resort under the theme of "onsen-ism" and is highly regarded not only for its springs but also for the town built around the Yubatake hot spring field. There are several hot spring sources, such as the "Bandaikou source" (6020 l/min), "Yubatake source" (4040 l/min), "Sainokawara source" (1073 l/min), "Nikawa source" (817 l/min), "Shirahata source" (659 l/min), "Netsu-no-Yu source" (298 l/min) and "Jizou source" (252 l/min). Each is among the most highly acidic springs in Japan. Altogether, the hot spring sources produce 32,300 liters of water per minute, which is the largest natural hot spring flow rate in Japan, without any motorized pumping from underground. Ekinariya Ryokan is ideally located, just a minute's walk from Yubatake source, the symbol of Kusatsu Onsen. The inn uses two types of sources: "Shirahata source" and "Yubatake source". The Shirahata source is said to have been discovered and bathed in by Minamoto no Yoritomo (1147-1199), the shogun who founded the Kamakura Shogunate, during his visit to Kusatsu in 1193. Near the Yubatake source, the largest public hot spring in Kusatsu Onsen, "Shirahata-no-Yu" also draws from this source. This small ryokan has a total of six rooms, but its unique feature is that each room has its own private onsen bath. In other words, each room has its own private hot spring bath that no other guests can enter until check-out. The owner herself handles the kitchen knives and serves the food to the guests. The inside of the inn is decorated with pressed flower art created by the landlady, creating a serene, relaxing atmosphere. Due to its small size, this hot spring inn allows guests to fully enjoy Japan's famous hot springs in a peaceful and intimate setting.
Travel Journal