ONSENIA is a curated guide to Japanese ryokans where you can enjoy authentic "Gensen Kakenagashi" — natural, free-flowing hot springs.

From luxurious ryokans perfect for special occasions, to rustic hideaways where time seems to slow down, to remote sanctuaries nestled in the wilderness— we introduce a diverse selection of onsen ryokans.

You step into the bath with excitement, only to catch a whiff of chlorine, like a swimming pool. …A bit disappointing, isn't it?

Even when a place is labeled "onsen," those that offer natural spring water—uncirculated and unchlorinated— are said to be quite rare.

Japan has a hot spring culture worth celebrating. Waters rich in unique minerals. Thoughtfully crafted bathing spaces. Moments of quiet immersion, surrounded by the sounds of nature. That perfect drink or meal waiting for you after the bath. "Yes, this is the kind of onsen experience I've been longing for." We want you to discover experiences like these. We want to discover more of them ourselves. That's why we started ONSENIA.

ONSENIA is run by a team that gets a little passionate when it comes to hot springs. The content we share is based on our own visits and firsthand experiences. While our update pace may be leisurely, we're steadily adding more ryokans to our collection.

When it comes to onsen data, we do our best to provide accurate information by referencing spring analysis reports, official sources, and literature. If you spot any errors or outdated details, we'd be grateful if you could let us know through our contact form.

In the future, we hope to create a space where onsen enthusiasts can share their voices too.

So, where shall we soak next?