Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Effortless float
LowHigh
Dense, salty water — you float without effort.
SodiumChloruresBrome
Furukawa Onsen Yuraku, in Matsuyama, Ehime Prefecture, offers sodium-chloride thermal water at 40°C, with an indoor bath, an outdoor rotenburo and a sauna.
Insider tip — Matsuyama is Japan's most bath-obsessed city, home to the legendary Dogo Onsen — the oldest certified hot spring in the country. While Dogo draws international visitors, Furukawa Onsen Yuraku is where Matsuyama residents bathe every day — the real local bath culture behind the famous façade. Matsuyama Castle, perched on a central hill, is one of Japan's twelve remaining original feudal castles. Haiku poet Masaoka Shiki was born here; the city's literary and bathing heritage run equally deep.