FUMOTO RYOKAN

Fumoto Ryokancurrently uses a private hot spring source located on the premises of its sister inn, Ryokan Kounoyu. The distance from the wellhead to the inn is approximately 500 meters, a distance considered short enough to maintain the freshness of the hot spring water. Drawn from a depth of 300 meters underground, the hot spring boasts a mineral-rich quality with abundant beneficial components. The spring water emerges at a temperature of 60.5℃ . To maintain a comfortable bathing temperature (40‒42℃), water is not added as much as possible. Instead, the temperature is adjusted using heat exchangers and by controlling the volume of water flowing into the baths. While most modern hot spring facilities manage water temperature through computerized systems, here, it is done by hand. This dedication to preserving the hot spring’s quality is truly admirable. According to the Hot Spring Analysis Reports, the dissolved substances (excluding gaseous substances), which are the active components of the hot spring, are 1,180 mg/kg. Since this exceeds 1,000 mg/kg, the spring qualifies as a “saline spring”, and the main components are listed in the spring quality name. That spring quality name is: Sodium, Calcium‒Hydrogen Carbonate/Sulfate/Chloride Spring. Yes, it’s a long name, but it serves as proof of the variety of characteristics of the hot spring. Simply put, it’s a unique blend of 3 spring qualities: hydrogen carbonate spring, sulfate spring, and chloride spring. Let’s look at each in more detail. 1. Hydrogen Carbonate Spring When sodium ions, the most abundant cation, and hydrogen carbonate ions, the most abundant anion, are combined, the result is a Sodium‒Hydrogen Carbonate Spring (formerly known as “Sodium Bicarbonate Spring”). Hydrogen carbonate softens the outer layer of the skin, making it easier to remove dead skin cells. This leaves the skin smooth and is why it’s often called “Hot springs for beautiful skin” with cleansing effect. In addition, it is also called “Hot springs for refreshing” or “Hot springs for cooling effect”, because the skin's protective power is weakened by the reduction of sebum, making it easier for moisture on the surface of the skin to evaporate, and bathing in it, especially during hot weather, provides a refreshing feeling afterwards. Hydrogen carbonate ion also enhances the cleansing effect on the skin and promotes disinfecting and sterilizing action on wounds, supporting healing for cuts. It also promotes the removal of dead skin cells while retaining moisture, which helps with dry skin as well. Furthermore, the carbon dioxide (CO₂) contained in the product is absorbed into the body through the skin, dilating peripheral blood vessels and improving blood flow, which has an effect on peripheral circulatory disturbance. As blood flow increases, symptoms of sensitivity to cold are alleviated.

2. Sulfate Spring When calcium ions, the second most abundant cation, and sulfate ions, the second most abundant anion, are combined, the result is a Calcium‒Sulfate Spring (formerly known as “Gypsum Spring”). This sulfate spring is called “Hot springs for anti-aging” because of its skin reviving and wrinkle stretching effects , and like “Sodium - Hydrogen carbonate spring (Sodium bicarbonate spring)”, it is also called “Hot springs for beautiful skin”. Furthermore, it is also known as “Hot springs for cuts” because of its ability to revive the skin. In addition, calcium ions have the effect of adjusting the contraction and dilation of blood vessels, stabilizing blood pressure and having a calming effect, and sulfate ions have the effect of dilating blood vessels, making them good for hypertension and arteriosclerosis, and “Calcium‒Sulfate springs” are also called “Hot springs for strokes ”. The indications by spring quality of sulfate springs include the same 4 items as hydrogen carbonate springs (cuts, peripheral circulatory disturbance, sensitivity to cold, dry skin ), with the addition of depression.

3. Chloride Spring The third spring quality is the Sodium‒Chloride Spring (formerly known as “Weak Salt Spring”). Salt forms a thin layer over the skin’s sweat glands, preventing evaporation of sweat and helping the body retain warmth after bathing. Because of this effect, it is commonly referred to as “Hot springs for warmth ”. The long-lasting heat-retention effect promotes balance in the autonomic nervous system and contributes to emotional stability. Additionally, by raising the body temperature, it may suppress the secretion of stress hormones and improve mood, showing potential benefits for depression . Furthermore, because it coats the skin, it works excellently as “Hot springs for finishing touch” after bathing in “Hot springs for beautiful skin”, locking in moisture and enhancing hydration. Due to the salt’s bactericidal properties, it is also known as “Hot springs for cuts”. In summary, the indications by spring quality of chloride springs match those of sulfate springs: cuts, peripheral circulatory disturbance, sensitivity to cold, dry skin and depression .
In addition to having the benefits of all 3 spring qualities, this hot spring has a neutral pH of 6.4, making it gentle and low-irritant—perfect for sensitive skin. Let’s take a closer look at the sodium ions and hydrogen carbonate ions. When their combined milliequivalent percentage exceeds 80%, the water is said to have a “silky-smooth” texture. This spring contains 52.96% sodium ions + 37.01% hydrogen carbonate ions, totaling 89.97%, so guests will truly feel the smoothness when they bathe. Furthermore, the amount of sodium hydrogen carbonate (also known as sodium bicarbonate)—a key indicator of hot spring quality—is 397 mg/kg, which surpasses the legal threshold of 340 mg/kg to qualify as an official hot spring. The hot spring also contains 251.4 mg/kg of metasilicic acid, a non-dissociating moisturizing component. This amount is more than 5 times the standard value for hot spring, and in this respect can also be called “Hot springs for beautiful skin”. Additionally, the spring contains 9.7 mg/kg of metaboric acid, which is known for its strong cleansing effects. This exceeds the 5 mg/kg threshold to qualify as a hot spring, and had it surpassed 10 mg/kg, it could be called “Hot springs for beautiful skin”. What makes this experience even more special is that the spring water is delivered directly from the source without circulation—a luxurious kakenagashi style—allowing guests to fully feel the natural benefits of the spring on their skin. One of the reasons this inn is so beloved is its use of an abundant private hot spring source, offering guests 3 types of open-air baths: public open-air baths, private open-air baths, and guest room open-air baths that can be enjoyed at any time of day, at your own pace.

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, which became very popular.
The entire town was captured as a single onsen ryokan, giving it a sense of unity, which won the sympathy of onsen fans.
It was the president and landlady of Fumoto Ryokan who came up with the idea for the "Onsen hopping pass", which is now commonplace in hot spring areas throughout Japan.
The inn is located on Kawabata-dori, the main street of Kurokawa Onsen, and has a total of 17 baths (2 open-air baths for men and women, 11 private baths including open-air baths, 3 open-air guest baths, and 1 footbath) for a total of 14 guest rooms, making it a true department store of hot springs.
The guest rooms are mainly rustic Japanese-style rooms, but there is also a guest room with an open-air bath and a bed in the annex.
The cuisine includes Kumamoto's famous horse sashimi and Higo beef, and is reasonably priced, so everything is highly rated.
You can truly feel the reason for the nationwide popularity of Kurokawa Onsen at this inn.
Travel Journal