Discover the Secret to Silky Skin: Kusatsu Onsen’s Pure Spring Water Soap

Infused with the Historic “Wakanoyu” Source

Unlike mass-produced soaps that use standard water, this soap is formulated using authentic, mineral-rich spring water from the historic “Wakanoyu” source.

In Kusatsu, different springs offer different mineral compositions and benefits. The Wakanoyu source—exclusively piped into the traditional, century-old Yamamoto-kan ryokan—is highly celebrated among onsen connoisseurs. It is famous for its remarkably soft texture compared to other intense Kusatsu springs, earning it a reputation as a “bidei-no-yu” (water for beautiful skin). This precious, time-honored water is beautifully preserved inside the soap, allowing you to wash your face with the exact same therapeutic elements enjoyed by ryokan guests for generations.

Powerfully Moisturizing with Collagen

Kusatsu’s natural acidic properties are incredible for purifying the skin, but to ensure a perfectly balanced wash, Yukemuri Soap is enriched with high-quality collagen. This powerful blend locks in moisture while you wash, ensuring your skin feels incredibly soft, plump, and deeply hydrated—never tight or dry.

Gentle Enough for Sensitive Skin

Formulated with a gentle, additive-free approach, this soap creates a rich, whipped cream-like lather that lifts away impurities without irritating the skin barrier. It brings the soothing, softening finish of a perfect Japanese bath straight to your sink, making it highly recommended for: