About Onsen Oni
Onsen Oni is a community-supported catalog and interactive map of hot springs in Japan. We're building the fullest, most detailed database of onsen available anywhere.
Our Mission
We aim to create the most complete, reliable, and accessible database of Japanese hot springs. From large resort complexes to hidden wild baths in the mountains, every onsen deserves to be documented with accurate, practical information.
Promoting Onsen Culture Internationally
Japan's bathing culture is one of its greatest treasures, yet much of the information about individual onsen is only available in Japanese. Onsen Oni is fully bilingual: every entry includes English and Japanese names, descriptions, and practical details, making onsen accessible to visitors from around the world.
Supporting Rural Japan
Many of the finest onsen are found in small towns and remote mountain valleys far from major cities. By highlighting these places, we hope to support local communities and help preserve authentic Japanese bathing traditions that have been passed down for centuries.
Community-Driven
Onsen Oni is built by people who love onsen. Contributions, corrections, and new discoveries are always welcome. Together we can map every hot spring in Japan.
The Society Behind Onsen Oni
Onsen Oni is run by the International Onsen Culture Exchange Society (Kokusai Onsen Bunka Koryukai, 国際温泉文化交流会). Our purpose is to document Japan's hot springs properly and to carry their culture to an international audience.
We work from the source. Our members travel to the springs, verify each entry on site, photograph the water-analysis certificates (onsen bunsekisho, 温泉分析書) posted at the baths, and turn what's written on them into something a visitor can actually understand. That research goes into a single bilingual catalog, open to everyone.
Partner With Us
We work with prefectures, onsen towns and associations, and ryokan. If you run a stamp rally, a yumeguri (湯めぐり) route, or a group of facilities, we can give it a proper home on the map: a dedicated program page in Japanese and English, accurate and maintained details for every facility, and an audience of onsen travellers in Japan and overseas who are looking for exactly this. We handle the research, the translation, and the build.
To talk it through, write to us at [email protected].
Contact
Questions, feedback, or partnership inquiries? Reach us at [email protected]