Masutomi Onsen

Masutomi Onsen is a lithium-bearing hot spring in Yamanashi Prefecture, in the Ogawa area of Hokuto City near the foot of the Yatsugatake Mountains, recognized as one of only four springs in Japan certified as containing notable concentrations of lithium, whose presence in the mineral water gives the source its distinctive character and reputation. The Yatsugatake volcanic mountains that rise along the border of Yamanashi and Nagano Prefectures form a dramatic backdrop for this distinctive mineral spring, and the surrounding highland landscape of larch forests, clear streams, and elevated meadows creates an exceptionally peaceful natural setting for the bathing experience at Masutomi. The lithium content of the spring water has attracted scientific and popular attention as interest grows in lithium-bearing mineral waters, making Masutomi Onsen a destination of both traditional well-being and contemporary curiosity.