Letters Home: Kusatsu Onsen, Gunma Prefecture

Continuing with my series of introducing places around Japan that may not be on people’s initial list of “must see” places, today I am introducing another hot spring or “onsen” town just north-northwest of Tokyo called “Kusatsu Onsen.”

Similar to Ginzan Onsen that I introduced in my last column, this lovely jewel of a town is also located deep in the mountains of rural Japan but is much more easily accessible from Tokyo and it doesn’t have the heavy snowfall that Ginzan Onsen has, but it boasts a lovely charm and uniqueness all its own. I visited around Christmas time and there was no snow, and the weather was quite pleasant. (photo below)

The town of Kusatsu Onsen has a population of around 7,000 people, but it welcomes millions of tourists and visitors every year (so it isn’t as much of a hidden jewel with regards to being a “secret” tourist spot as other onsen towns seem to be, I guess). 

Since it is about a three-hour trip from Tokyo Station, it is regarded as a day trip destination from Tokyo, which is why it welcomes so many tourists each year. While I do recommend staying overnight at least one night to get the full onsen experience, an early train there, and a late train back to Tokyo is quite doable.

Kusatsu Onsen boasts having the largest volume of water of all the free-flowing hot springs in Japan, and it is consistently listed as being one of the top three hot spring towns in Japan.  It has 100% natural spring water, meaning that no mineral water has to be shipped into the city.

Some onsens in Japan use 100% natural mineral water, but the water is sometimes shipped in from outside the area.  Not Kusatsu Onsen — which is the actual source of all of its hot spring water, and it is widely regarded as being highly therapeutic with a strong anti-bacterial consistency that people claim to have extraordinary healing properties.

I read that E-Coli cannot survive even a moment in these waters, showcasing its anti-bacterial properties. 

In Kusatsu, over 32,000 liters of mineral water gushes forth every minute of every hour, which amounts to some 230,000 barrels per day. That is a lot of water!

Why does this town have such an abundance of hot spring water? The answer is found with the active volcano that is the source of the waters, called Mount Shirane. In fact, hot steam rises up all around the town from the ground, so visitors can see clearly the hot steam from just about anywhere in the town.

According to the town’s official website, the legend is that it was discovered some 1,800 years ago by Yamato Takeru (a Japanese folk hero and legendary prince called Prince Ousu); another theory is that the Buddhist high priest Gyouki of the Nara Period (710-784) actually found it first.

No matter who first discovered the therapeutic waters and introduced them to the general population, the hot springs have been loved and frequented by countless people since that time. They were especially popular with the shogun and samurai class of nobility. But it was actually a European doctor from Germany that brought Kusatsu Onsen to the world’s attention in the early 20^th century. 

Dr. Erwin von Balz first analyzed the hot springs’ mineral waters and developed a therapeutic bathing method while boasting about its exquisite location that had an abundance of nature and fresh air, with delicious drinking water. After he wrote about the hot spring, it became somewhat of a spa resort which continues to this day.

The mineral waters have a very high level of acidity, which in turn offers bathers strong curative benefits as well as sterilizing qualities. 

The primary minerals in the spring water are sulfur, aluminum sulfate and chloride. So, many bathers suffering from physical ailments such as muscular pain or arthritis, skin conditions, sore shoulders or sprained limbs will find relief from the curative properties in the waters. In addition, people who suffer from diabetes, high blood pressure, hardening of the arteries, claim to be helped from soaking in and convalescing in Kusatsu Onsen’s waters.

Most Japanese people readily know about Kusatsu Onsen even if they live far away from it. A famous expression in Japanese extolls its virtues with the saying “Kusatsu yoi toko, ichido wa o-ide!”

In English, this roughly translates to: “Come to Kusatsu once in your life, since it is such a wonderful place.”

Another unique feature of the town, and which is also one of its most well-known symbols, is the yubatake (“a field of hot water”). (photo)

Long wooden planks were constructed into channels in the center of the town that guide the hot spring water to the various bath houses found in and around the town and in inns. This wood is thick pinewood or Japanese cypress which is believed to be the best material to construct bathtubs, too, because this wood can withstand the high acidic content of the waters the best.

Even though they don’t stay pretty or new looking for very long, old wooden tubs are the preferred material for many inns in the area.

One very interesting activity that visitors like to watch is the “yumomi,” which is a traditional ceremony performed at “Netsu no Yu” (a traditional building near the center of the town). This is the age-old ritual of cooling down the hot spring waters in Kusatsu. (photo above)

The women, in synchronized motions, use large paddles to stir the hot spring waters in order to cool them. The hot spring has a temperature of between 123 and 201 degrees, which is much too hot to bathe in without it being cooled down. In order not to dilute the natural spring water that is full of minerals with cold tap water, this system was devised during the Edo Period (1603-1868).

The ceremony is conducted in the morning and afternoon, and before each performance, visitors must secure a ticket to observe it. It is best to arrive early to get your tickets and early enough to get a good viewing spot. Women on each side of the bath area take large paddles and stir the water rhythmically to an old, traditional song to pace their churning of the waters. (photo)

This is a ceremony that is unique to Kusatsu and very much worth observing. If I remember correctly, at the end of the ceremony some of the visitors were invited down to try their hand at churning the water, and the women performed a traditional dance on the stage located to the back of the paddle area.

While it seems like it would be too touristy to be enjoyed, it really was not. It gave the feeling of a tradition that is unique to the area and the majority of the tourists when I observed it were actually Japanese people who were visiting the town.

For onsen afficionados, it is a must visit to relax and enjoy the therapeutic waters with curative healing benefits. I plan to write about yet another onsen town in my next column, so you will have lots of choices to consider once you visit Japan for yourself.