The facility is intentionally designed to be rustic and unpretentious, with the name 'Hottarakashi' translating roughly to 'left alone' or 'neglected'.
The water contains high levels of sodium and bicarbonate, which are traditionally associated with skin-softening properties.
Unlike many traditional Japanese hot springs, the baths are positioned to face the sunrise, making them a popular destination for early morning visitors.
The two bathing zones, Acchiyu and Kotchiyu, have different source springs and slightly varying mineral compositions.
The onsen is located on a former orchard site, preserving the original rural topography of the area.
Hottarakashi Onsen is a hillside hot spring facility in Yamanashi Prefecture known for its panoramic, unobstructed views of the Kōfu Basin and Mount Fuji. The facility features two distinct outdoor bathing areas, 'Acchiyu' and 'Kotchiyu,' which are fed by separate natural alkaline springs. The water is categorized as a simple alkaline spring, noted for its high temperature and transparency. The site is situated on a slope 700 meters above sea level, providing visibility of the city lights below at night. Visitors can access a dedicated rest area, 'Ikoi-no-Ma,' for post-bath relaxation. The baths are completely open-air, with no glass barriers between bathers and the mountain landscape.
Bring your own towels and toiletries, as they are available for purchase but not provided for free.
Use the onsite locker facilities for valuables, as they are not permitted in the bathing area.
Check the local weather forecast specifically for visibility, as heavy clouds or fog often obscure the view of Mount Fuji.
Do not wear swimsuits in the communal baths, as they are strictly prohibited.
Open daily throughout the year; no regular closure days.
Traditional Japanese onsen rules apply: remove all clothing before entering, rinse thoroughly before submerging, and ensure long hair is tied up to prevent it from touching the water.
