Tama Genryu Onsen Kosuge no Yu
Kosuge-mura, Yamanashi, Japan
Illustration photo — not a verified picture of this exact spot.
- Location
- Kosuge-mura, Yamanashi, Japan
- Water type
- bicarbonate, thermal
- Temperature
- 40 °C
- pH
- 8
Water profile
Thermicity
Sedative
LowHigh
Relaxing — deep, immediate muscle release.
Mineralisation
Restorative
LowHigh
Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
BicarbonatesSodiumCalcium
Tama Genryu Onsen Kosuge no Yu, in Kosuge village, Yamanashi Prefecture, taps bicarbonate thermal water at 40°C with a pH of 8, offering an indoor bath, an outdoor rotenburo and a sauna.
Insider tip — Kosuge-mura is the source village of the Tama River (多摩川源流) — the headwaters of the same river that supplies much of Tokyo's drinking water before flowing through Okutama and the Tama River valley. 'Tama Genryu' (Source of the Tama) onsen gives visitors the extraordinary experience of bathing at Tokyo's water origin, in a pristine mountain community of 750 residents surrounded by ancient cedar and hardwood forests. The village produces exceptional watercress and clear mountain stream trout.
Nearby
Frequently asked questions
How hot is the water?
The water runs quite hot here, around 40 °C — a sedative water that brings immediate muscle release.
What type of water is found here?
This spot features bicarbonate & thermal water.
What is the best season to visit?
The most favourable period for this spot is: Toute l'année.