Hinokamionsen is a hot spring located at the foot of Mount Funatsuyama (1,142m), the legendary setting of the Yamata no Orochi myth from Japan''s ancient Izumo mythology, in Takezaki, Okuizumo Town, Nita District, Shimane Prefecture. Situated at approximately 550 meters elevation near the headwaters of the Hii River, this area has long prospered through tatara iron smelting and is surrounded by lush greenery, clear streams, and a serene mountain environment. In the late 1980s, Yokota Town (now Okuizumo Town) developed three source springs, establishing the area as a hot spring destination. The spring gained national recognition when researcher Satoshi Fujita of the Central Hot Spring Research Institute selected it as one of Japan''s Three Great Beauty Hot Springs alongside Ureshino Onsen in Saga Prefecture and Kitsuregawa Onsen in Tochigi Prefecture.

The spring quality is an alkaline simple hot spring (hypotonic, alkaline, low-temperature spring) boasting an exceptionally high pH of 9.9. The source temperature is approximately 26.4 degrees Celsius as a cold mineral spring, containing 45.6mg of metasilicic acid. The colorless, transparent, tasteless, and odorless water has a silky, lotion-like texture, leaving skin remarkably smooth and supple after bathing. The water is heated to a comfortable bathing temperature.

Hinokamiso is a public hot spring facility located at the trailhead of Mount Funatsuyama, featuring an indoor bath with large windows overlooking the changing seasons. The old building houses a rock bath that is specially opened on the first and third Sundays of each month. The facility is known for its handmade soba noodles using locally grown buckwheat flour from Okuizumo Town, and has also introduced tent saunas available by reservation. Day-trip bathing costs 500 yen for adults and 250 yen for children. Operating hours are 10:00-19:00 (last admission 18:30), closed Tuesdays (closed Tuesdays and Wednesdays from December to February). Note that overnight accommodation reservations have been suspended since January 2022.