A historic hot spring area located at 900m elevation on the mid-slope of the Azuma mountain range in Yonezawa City, Yamagata Prefecture. With over 700 years of history since its opening, it is counted among the Yonezawa Eight Hot Springs.

During the Edo period, it was counted among the Ōu Three High Hot Springs along with Takayuzawa in Fukushima and Zao in Yamagata, with over 400 years of history as a hot spring cure resort. It was treasured as a secret recuperation spot for Yonezawa domain samurai during the Edo period, and became accessible to the general public from the late Edo era.

During the Warring States period, Date Terumune is said to have bathed here, and from 1604 to 1615, a gun manufacturing facility of the Yonezawa domain was located here.

Spring quality is sulfur-containing calcium-sulfate spring, with 3 naturally flowing sources. Source temperature about 57-60°C, pH 7.3 (neutral), currently nearly colorless transparent. Said to have wide-ranging benefits for wounds, burns, nerve pain, chronic gastrointestinal diseases, arteriosclerosis, chronic skin diseases, chronic women's diseases, diabetes, high blood pressure, and more.

The hot spring area has 4 ryokans including Higashiya Ryokan, Nishiya, and Nakaya Bekkan Fudokaku, with total capacity of 268 people. Particularly, Nishiya has a main building with a 200-year-old thatched roof gassho-zukuri structure remaining from the Edo era, with a bathroom said to be built from granite in late Edo period featuring a waterfall bath remnant of the hot spring cure tradition. After 700 years, natural hot springs still overflow abundantly into the baths.

Snow-deep in winter with an atmospheric 'secret realm' ambiance, truly conveying the atmosphere of a secret hot spring from the Edo era.