Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
BicarbonatesSodiumCalcium
Kiyose, in the northwestern Tokyo Metropolis on the Seibu Ikebukuro and Kokubun-ji Lines, is a leafy residential community known for the Kiyose Sanatorium established in the early twentieth century that attracted patients seeking clean air in the forested Musashino plateau, creating a neighbourhood culture of quiet retreat that has shaped the pleasant residential character of the city to the present day. Kiyose Onsen Tokyo draws on sodium and bicarbonate thermal waters from the geological resources of the northwestern Tokyo upland, offering restorative baths in a residential community whose sanatorium heritage, the forested Yanase Stream green corridor, and the traditional Musashino woodland atmosphere create a genuinely relaxing and unhurried spa setting within the Tokyo metropolitan boundary. The Yanase Stream natural corridor cycling and walking path, the historic Kiyose Sanatorium garden, and the green residential character of this well-preserved Musashino plateau community make Kiyose a pleasantly calm and naturally connected spa destination in the northwestern reaches of Tokyo Metropolis.
Insider tip — Kiyose occupies the northeastern fringe of the Musashino Plateau where the Yanase River creates a modest green belt through suburban streets, and its sento offers bicarbonate water at 40°C that the local community has relied on for personal hygiene and relaxation across generations. The alkaline waters are particularly kind to dry winter skin, and attendance peaks in December when cold winds sweep down from the Kanto Mountains. A generous rest lounge with manga shelves and cold beverages is standard, encouraging unhurried recovery between soaks. Kiyose is also the gateway to Higashimurayama Reservoir Park, making a combined walk-and-soak day trip easy to organise.