Kusatsu Onsen, Gunma Prefecture "Yunohana" (Hot Spring Flower) I purchased several of these locally. Brand new, unopened. This is made by collecting and drying crystallized hot spring components. It is collected from the Yubatake (hot spring field) in Kusatsu Onsen and is a rare product, with only about 4,000 pieces produced annually. It is sold only at ryokans (Japanese inns) and souvenir shops authorized by the Kusatsu Town Chamber of Commerce and Industry. I purchased these after visiting several shops. * It is a yellowish powder that contains sulfur, which makes your skin smooth. The effects of sulfate springs warm the body from the core. Kusatsu Onsen is a strongly acidic hot spring. It is effective for skin diseases (athlete's foot, heat rash, eczema, scabies, etc.), neuralgia, insect bites, rheumatism, hemorrhoids, cuts, chapped skin, chilblains, acne, sprains, hives, prickly heat, rough skin, and abrasions. How to use Yunohana: For a standard unit bath, dissolve 1-2 coffee spoons of Yunohana in the hot water, mixing it in. It dissolves easily. You can also dissolve a pinch in a washbasin of hot water and soak the affected area for sufficient effect.