Yufu-no-Oyado HOTARU

Yufuin Onsen is the second largest hot spring in Japan in terms of the amount of water gushing from its sources, following Beppu Onsen in Oita Prefecture, the same prefecture where Yufuin Onsen is located. Most of its springs are simple hot springs, but each of the source wells in the Yufuin basin has slightly different characteristics.
Yufu-no-Oyado HOTARU's spring water is an Alkaline simple hot spring with a Hydrogen ion concentration (pH value) of 9.7, one of the highest among Yufuin's hot springs. Since human skin is generally slightly acidic, soaking in alkaline hot spring water causes the surface of the skin to react and dissolve dead skin cells. This results in a silky smooth skin texture. However, because the pH value of the hot springs here is particularly high, the texture of the hot spring water is more than smooth; it would be more accurate to describe the water as thick and creamy. The feeling of the water clinging to the skin can be felt as soon as one takes a bath. The clear, colorless water is also referred to as "Hot spring water like lotion" by regular visitors.
After bathing, the skin feels smooth and renewed because the dead skin cells have been removed. The alkaline nature of the water is one of the conditions for its being called "Hot spring for beauty".
Since dead skin cells are removed, skin metabolism is also activated. The skin tissue newly created by bathing comes to the surface in about a one-month cycle, depending on the individual, so it is known that the skin beautifying effect can be obtained not only immediately after bathing, but also about one month later. However, it is important to note that there may be hidden pitfalls even in the beautiful skin baths. The removal of dead skin cells means that a barrier on the surface of the skin is removed. In other words, the skin is more prone to dryness, so in the winter when the air is dry, or if you have dry skin to begin with, you should put on some cream after taking a bath.

Also, we would like you to look at the sodium ions and bicarbonate ions again. There is a rule of thumb that says that a "smooth" feeling is produced when the sum of these two (millivalent %) exceeds 80%. In other words, according to the hot spring analysis report, this hot spring has 98.27% sodium ions + 27.78% bicarbonate ions = a total of 126.05%, which significantly exceeds 80%, so you will definitely feel this when you bathe in it.

Note the components that do not appear in the name of the spring. Metasilicic acid is contained at 123.8 mg/kg per kilogram of spring water, more than twice the regulation value (50 mg/kg). Metasilicic acid is a natural moisturizing component and is sometimes used as an component in some lotions. It has a moisturizing effect and leads to moist skin after bathing. The presence of metasilicic acid is one of the conditions for being called "Hot spring for beauty". The alkaline component removes excess dead skin cells from the skin, and the moisturizing component metasilicic acid penetrates into the skin. This hot spring is a double delight for one bath.

A simple hot spring is a hot spring with less than 1,000 mg of dissolved substances in 1 kg of the source. Because of the low dissolved substances, this type of hot spring is said to be "Gentle hot spring" because it is hypoallergenic. Therefore, it is said to have a particularly relaxing effect, and indications unique to this spring include Autonomic instability, Insomnia, Depression, and other mental health issues.
It is a well-known fact among hot spring connoisseurs that it is not so simple when explaining simple hot springs. Even if the amount of dissolved substances is small, when bath additives on the market are used at home, the amount of dissolved substances per kilogram is about 50 to 150 mg, i.e., simple hot spring is often many times more thick compared to the bath additives. In fact, the dissolved substance in the source here is about 300 mg/kg, so it is considered to be two to six times more concentrated.
Nevertheless, the greatest advantage of simple hot springs is that they are hypoallergenic, so people of all ages and both sexes can bathe in them slowly. Because simple hot springs are less stimulating, they are sometimes used for stroke rehabilitation, and are therefore sometimes referred to as "Hot spring for stroke" or "Hot spring for neuralgia".

The temperature of the spring water is 43.6°C, which is the ideal temperature for a free-flowing hot spring water. Free-flowing hot spring water is a luxurious use of water, in which the hot water is poured into the bathtub and any overflow is disposed of as it is. The possibility of always being able to soak in fresh hot spring water is a great attraction for hot spring enthusiasts. If the temperature of the source is not at the perfect level, it is necessary to go extra steps to make the hot spring flow, such as adding tap water to lower the temperature or using a boiler to raise the temperature, which may compromise some of the original power of the hot spring. This process is also costly. The temperature of the spring is also important, especially for those who are particular about hot springs.
In the case of free-flowing hot spring water (when no chlorine or other disinfectants are used), it is said that a standard amount of 1 liter/minute of spring water per person in the inn is necessary to keep the baths clean and enjoyable. The hot spring here is about twice the standard value, which means that the source can be used in a luxurious and hygienic way.
Furthermore, the hot spring here is a private source. The benefits of this are that the distance between the spring and the baths is close. This reduces the risk of impurities mixing with the hot spring water before it is poured into the baths, and most importantly, the hot spring water is fresh and ready to soak. The further away the hot tub is from the spring, the more likely it is that the hot spring components will deteriorate. Whether or not a hot spring has its own hot spring source is a point that hot spring enthusiasts should not overlook.
The hot spring here is 100% free-flowing hot-spring water, which is poured into the large baths, private baths, and open-air baths in guest rooms. Once you soak in the famous hot spring with its particular use of hot water as mentioned above, you will be so surprised by the tender feeling of the hot spring that you may say that this hot spring is so sinful that your impression of other hot springs in Yufuin may fade away.

"Yufu-no-Oyado HOTARU" is a hot spring inn located a little far from the central area of Yufuin Onsen. Its location overlooking Mt. Yufudake is also an attractive feature of this ryokan.
You can experience the lotion-like hot spring water from its own hot spring source in the men's and women's open-air baths, as well as in the private baths available free of charge.
The guest rooms are in a detached style with a roofed corridor connecting them. The guest rooms include a variety of types, such as a guest room with an open-air bath made of rocks, a Japanese-style room with a half-open-air hinoki bath, a Japanese-style room with two adjoining rooms with a great view, and a Western-style room for the barrier-free.
The inn's atmosphere, which enhances a sense of the extraordinary, and its sumptuous dinner prepared by a veteran chef with a special attention to detail, yet at a reasonable price, make it a popular choice for many repeat guests.
Once you stay here, you will see that the owner's wish is strongly reflected: "I want anyone to feel free to come and enjoy this hot spring and know what Yufuin has to offer".
Travel Journal