The spring is called Hazami Onsen. It is a bicarbonate spring notable for its slightly viscous, silky feel that leaves skin smooth. All three indoor baths are provided 100% from the source with no added water, no reheating, and no circulation. In the outdoor baths you can enjoy the river's murmur by day and a star-filled sky by night. The high-concentration carbonated spring, enjoyed by soaking at a lukewarm temperature, is nicknamed 'Heart Bath' and is known for its strong circulation-promoting effects. It is also traditionally regarded as beneficial for conditions such as hypertension, diabetes, and atopic dermatitis.

When you sink into the mildly warm water, fine carbonic gas gently dilates blood vessels, warming you slowly from the core. Although it is a low-temperature bath, you can bathe for a long time, and your body will feel remarkably light afterward. Combined with the source-fed natural hot spring baths, you can select the water best suited to your needs.