Mimata Onsen is a hidden hot spring in the mountains of Kanagi Town, Hamada City, Shimane Prefecture, with a history dating back to 1864 (Genji 1). The hot spring village is formed near the confluence of the Kakoya River and the Oibara River, and Kameya Ryokan is a three-story reinforced concrete Japanese-style inn standing along the river in the center of the village. When the spring was first discovered, the area was called "Yunotani" (Valley of Hot Water), and hot water seeped out from cracks in the rocks along the roadside. During the Russo-Japanese War, a convalescent facility for the Hamada 21st Infantry Regiment was established here. In the Onsen Sousenkyo (Hot Spring General Election), Mimata Onsen has won first place nationally in the "Beautiful Skin Category" for three consecutive years, earning nationwide recognition as having "the best water quality in Japan for beautiful skin."

The water is classified as an alkaline simple hot spring with an exceptionally high pH of 9.9. The source temperature ranges from 47.1 to 47.4 degrees Celsius. Though colorless and transparent, the water has a distinctive silky, slippery texture that clings to the skin — its most celebrated characteristic. Rich in metasilicic acid, which promotes skin keratinization, the high pH value creates a synergistic effect that delivers outstanding skin regeneration benefits. The water also contains sodium and carbonate ions, removing old keratin while moisturizing the skin. Therapeutic indications include neuralgia, rheumatism, bruises, cold sensitivity, fatigue recovery, and post-traumatic healing.

The inn features two main baths: the men''s bath "Susano-o" and the women''s bath "Inadahime," named after figures from Japanese mythology. In addition to indoor baths, an outdoor bath is available, and private bathing can be arranged under certain conditions. With only 8 guest rooms, it is a small-scale inn offering three room types: 8-tatami Japanese rooms, 14-tatami Japanese rooms, and Japanese-Western rooms. All rooms are equipped with heated toilet seats and refrigerators. The cuisine, featuring local seasonal ingredients including nodoguro fish, abalone, and Wagyu beef from the San''in region, is highly praised. Day-trip bathing is available for 510 yen for adults and 360 yen for children, from 14:00 to 20:00. Free parking for 9 vehicles.