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 classification as an “Acidic spring” is that the hot spring water contains 1 mg or more of hydrogen ions per kilogram. As indicated by the pH value (hydrogen ion concentration) of 2.0, acidic springs often show strong acidity.
They have strong bactericidal properties, helping to suppress bacteria and viruses on the skin. The indications by spring quality include Atopic dermatitis, Plaque psoriasis, and Epidermal suppuration.
Acidic springs are also considered effective for conditions such as trichomoniasis and athlete’s foot. Because they help eliminate a wide range of causes of skin-surface problems, they are often referred to as “Hot springs for skin diseases”.
In addition, bathing in an acidic spring promotes blood circulation, which helps improve glucose metabolism and supports the action of insulin. For this reason, Impaired glucose tolerance (diabetes) is also included among the indications by spring quality.

Next, one of the conditions for classification as a “Sulfur spring” is that the hot spring water contains 2 mg or more of total sulfur per kilogram (the sum of (1) hydrogen sulfide ions, (2) thiosulfate ions, and (3) free hydrogen sulfide).
Sulfur springs are further divided into two types: the “Sulfur type”, in which (1) and (2) are the main components, and the “Hydrogen sulfide type”, which contains a higher amount of (3). Here in Kusatsu Onsen, the spring is classified as a “Hydrogen sulfide type Sulfur spring”.
The water often appears milky white, and its indications by spring quality have much in common with those of an “Acidic spring”.
Like acidic springs, sulfur springs have strong bactericidal properties and are considered “Hot springs for skin diseases”, effective for a wide range of skin-surface problems.
The indications by spring quality, including Atopic dermatitis, Plaque psoriasis, and Epidermal suppuration, are shared with acidic springs, which also have strong bactericidal properties. Sulfur springs, however, additionally include Chronic eczema.
This is because sulfur springs not only have bactericidal properties but also help promote metabolism and reduce inflammation.
Sulfur springs also help remove excess sebum, making them particularly suitable for acne-prone and oily skin. They may also provide a skin-brightening effect by promoting metabolism and helping the body eliminate melanin. For these reasons, sulfur springs are also known as “Hot springs for beautiful skin”.
One important precaution is to remove rings, necklaces, and other metal accessories before bathing, as sulfur components can cause metals to discolor.
In addition, Hydrogen sulfide is absorbed through the skin and dilates peripheral blood vessels, helping improve blood circulation. For this reason, Peripheral circulatory disturbance is included among the indications by spring quality for Hydrogen sulfide type Sulfur springs.
Furthermore, Hydrogen sulfide type Sulfur springs are known as “Hot springs for phlegm” because they may help relieve asthma and make it easier to clear phlegm.
Contraindications by spring quality for bathing include people with sensitive skin or mucous membranes and elderly people with dry skin (the same as for Acidic springs).
In other words, like Acidic springs, Sulfur springs are highly stimulating and require particular caution for people in poor health, elderly people, and those with sensitive skin, as they are more likely to experience Hot spring fatigue.
The combination of “Acidic spring – Hot springs for bactericidal purposes” and “Sulfur spring (Hydrogen sulfide type) – Hot springs for beautiful skin” is often found in Meito (renowned hot springs).
However, it is important to remember that the stronger the effects, the greater the potential burden on the skin.

The third spring type is the “Sulfate spring”. One of the conditions for classification as a Sulfate spring is that Sulfate ions are the main anion component.
The Hot Spring Analysis Report shows that the water is rich in aluminum ions among its cations. These combine with sulfate ions, making the spring what was formerly known as “Myoban-sen (Alum spring)”.
Its astringent action, which causes tissues and blood vessels to contract by denaturing proteins, helps tighten the skin and also activates metabolism and promotes skin revitalization.
As a result, in addition to Cuts, which are included among the indications by spring quality, it is considered effective for burns, acne, psoriasis, itching, and chronic eczema. For this reason, Sulfate springs are also known as “Hot springs for cuts”.
Sulfate springs are also known as “Hot springs for stroke prevention” because sulfate ions help increase the amount of oxygen delivered through the blood.
This blood-circulation-promoting effect is also why Peripheral circulatory disturbance and Sensitivity to cold are included among the indications by spring quality.
Furthermore, Sulfate springs help regulate the autonomic nervous system, contributing to stress reduction and emotional stability. For this reason, Depression is also included among the indications by spring quality.
Sulfate ions also help replenish moisture in the skin, which is why Dry skin is included among the indications by spring quality.
In addition, Sulfate springs have an anti-aging effect that helps give the skin firmness and moisture, earning them the name “Hot springs for rejuvenation”.
In this respect, like Sulfur springs, they are also known as “Hot springs for beautiful skin”.

Finally, the fourth spring type is the “Chloride spring”, in which chloride ions are the main anion component. It has the same five indications by spring quality as the Sulfate spring.
The salt in Chloride springs has bactericidal properties, making this spring type a typical “Hot spring for cuts”. It is therefore natural that Cuts are included among its indications by spring quality.
Chloride springs are also known as “Hot springs for warmth”.
This is because the salt adheres to the skin and forms a film. Even after bathing, this film acts like a pack and blocks the sweat glands, helping slow the loss of body heat through perspiration.
This highly effective heat-retaining action keeps the body warm for a long time, which is why Peripheral circulatory disturbance and Sensitivity to cold are included among the indications by spring quality. Sensitivity to cold is also an indication for other spring types, but Chloride springs are considered particularly effective in this respect.
This salt pack also helps prevent the skin from drying out after bathing, which is why Dry skin is included among the indications by spring quality.
Furthermore, as with the Sulfate spring mentioned earlier, the long-lasting heat-retaining effect associated with springs known as “Hot springs for warmth” helps regulate the balance of the autonomic nervous system and promotes emotional stability. The rise in body temperature may also help suppress the secretion of stress hormones and contribute to an improved mood. For these reasons, Depression is included among the indications by spring quality.

The amount of “Metasilicic acid”, a non-dissociated component other than cations and anions, is also noteworthy.
The spring water contains more than 200 mg/kg, which is more than four times the hot spring standard (50 mg/kg).
Metasilicic acid is used as an ingredient in some skin lotions and has a moisturizing effect. Hot springs containing high levels of metasilicic acid can therefore be considered “Hot springs for beautiful skin”.
Furthermore, the amount of “Metaboric acid” is also remarkable. It is present at nearly twice the hot spring standard (5 mg/kg).
Metaboric acid has a cleansing effect, is used in some eye drops, and is also said to be effective against acne.

As described above, this exceptional spring quality is truly worthy of being called one of “Japan’s Meito (renowned hot springs)”. The way this precious hot spring water is used is also thoroughly managed.
The baths use “100% natural free-flowing hot spring water”, with no circulation, filtration, or disinfection. Fresh hot spring water is continuously poured into the baths, overflowing and constantly being replaced with fresh spring water.
Temperature control also requires considerable effort. Taking the day’s air temperature into account, the inn staff manually adjust the amount of hot spring water flowing from the outlets into the baths to maintain the proper bathing temperature. This daily work must require a great deal of time and effort.
Kusatsu Onsen boasts Japan’s largest volume of naturally gushing hot spring water, with the spring water rising naturally without being pumped from underground by motors. As described above, the hot spring water is also exceptionally rich in beneficial components.
Interestingly, the hot spring water is clear and colorless immediately after it gushes from the source, but it can appear milky emerald green, as seen at the Yubatake.
This distinctive color is said to be related to a microorganism called “Ideyukogome”.
Ideyukogome is a type of single-celled algae that thrives in the harsh environment of acidic hot spring water, and Kusatsu Onsen is said to be its largest habitat in Japan.
We hope you will fully experience this blessing of nature and gift from the earth.

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 1200 ⅿ 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.
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