Daimaru Ryokan

To soak in the world's best carbonated spring at the Lamune Onsen in Nagyu Onsen, I stayed one night at the Daimaru Ryokan. 1. The Daimaru Ryokan has a history of over 100 years, built along the Serikawa River. The exterior is understated, but the interior exudes the air of a classic luxury inn. At the front desk sat a woman in a kimono and heavy makeup; she was not young, but her beauty was still evident. In Japan, good inns are often run by beautiful women. The hotel rooms were nice, with views of the Serikawa River in full bloom. The hotel also displayed many artworks, giving it a strong old-money feel. 2. The main reason for staying at the Daimaru was to soak in the carbonated spring. The hotel's onsen is also carbonated, but the water temperature reached 46 degrees Celsius, and the carbonic acid had dissipated. Later, Daimaru Ryokan built the "Lamune Onsen" a few hundred meters away. The open-air bath there has a water temperature of only 32 degrees Celsius, with abundant carbonated bubbles. Soaking in it feels like soaking in soda water—a tingling, numbing sensation, with your whole body enveloped in bubbles—a truly magical experience. There's also a sauna nearby; you can steam and then soak, which is incredibly relaxing. 3. Staying at Daimaru comes with a perk: free access to the "Lamune Onsen." To get to the "Lamune Onsen" from Daimaru, you walk along the Serikawa River, passing a crab-shaped open-air pool—a spot where the hot spring flows by the river. People can bathe for free, but they must not wear clothes or intentionally expose themselves. I thought no one would use it, but surprisingly, some did. There's a warning sign on the roadside near the onsen entrance: watch out for a cat crossing the street, as a cat often crosses the road to visit the onsen. 4. Bottled hot spring water can be purchased at both the onsen and Daimaru Ryokan. Many hot springs in Japan have drinkable water, but most don't taste as good as Nagayu Onsen; its water is truly refreshingly sweet. The meals included in the one-night stay are also quite good.