The name "simple hot spring" often leads to the misconception that it is "dilute" or "ineffective." However, this is a complete misunderstanding. Simple hot springs are the most prevalent and beloved type of onsen in Japan.
What is a Simple Hot Spring?
A simple hot spring refers to a spring with less than 1,000 mg of dissolved substances per kilogram of hot spring water (excluding gaseous substances).
It's not that there are "few components," but rather that "specific components do not reach the specified levels." Simple hot springs contain various minerals and components. According to the Onsen Law, if the source temperature is 25°C or higher, it is recognized as an onsen even if the dissolved substance content is low.
Appearance and Characteristics
Color: Colorless and transparent
Odor: Odorless or faint sulfur smell
Texture: Silky and soft
pH: If weakly alkaline (pH 8.5 or higher), it is called "alkaline simple hot spring."
While it may not be flashy, its "ordinariness" is its charm.
Why is it the Most Common in Japan?
Japan is a volcanic country with hot springs emerging nationwide. Among these, springs without prominent specific components are classified as simple hot springs. It is said that about 40% of Japan's hot springs are simple hot springs.
The Appeal of Low Irritation
The greatest advantage of simple hot springs is their low irritation.
Due to the low concentration of components, they are gentle on the skin. Even those with sensitive skin can enjoy them with peace of mind. You can soak for a long time without getting tired, allowing you to enjoy the onsen leisurely. From babies to the elderly, anyone can bathe safely, making it ideal for family trips.
Beauty Benefits of Alkaline Simple Hot Springs
Alkaline simple hot springs with a pH of 8.5 or higher are popular as "beauty baths."
Alkaline hot springs soften and remove old keratin from the skin. This is why your skin feels smooth after bathing. Alkaline hot springs combine beauty benefits with gentleness.
Main Benefits
Common indications for simple hot springs:
- Chronic pain or stiffness in muscles or joints
- Muscle stiffness in cases of motor paralysis
- Sensitivity to cold, peripheral circulation disorders
- Decreased gastrointestinal function, mild hypertension
- Symptoms due to stress (sleep disorders, depressive states, etc.)
- Recovery during convalescence, fatigue recovery, health promotion
Its ability to address a wide range of symptoms is a feature.
Notable Simple Hot Springs
Gero Onsen (Gifu Prefecture): One of Japan's three famous hot springs. Known as a "beauty bath" for its alkaline simple hot spring.
Kinugawa Onsen (Tochigi Prefecture): A popular onsen area with good access from Tokyo.
Towada Lake Onsen (Aomori Prefecture): A hot spring emerging by the beautiful lakeside.
Yugawara Onsen (Kanagawa Prefecture): A hot spring area loved by literary figures and artists since ancient times.
Recommended For
Onsen beginners, those with sensitive skin, small children, the elderly, those who want to soak for a long time, and those who prioritize relaxation. The appeal of simple hot springs lies in their low irritation and universal enjoyment.
Conclusion
Simple hot springs are the most common and beloved onsen in Japan. Although often misunderstood due to the name "simple," their gentleness and safety are their greatest attractions. They offer low irritation and can be enjoyed by anyone. At the same time, they provide ample basic benefits of onsens, such as fatigue recovery, stress relief, and beauty effects.
Whether you're experiencing an onsen for the first time or are a seasoned onsen enthusiast, enjoy the softness and gentleness of simple hot springs. This is the foundation of Japanese onsen culture.
