Yumo.to - A Japan-wide onsen map with tattoo and water filters

Hi Product Hunt, I built Yumo.to because onsen information in Japan is surprisingly fragmented. Booking sites are useful if you already know where you want to stay, but they are not great when you just want to answer basic questions like: - where can I find an onsen nearby? - is tattoo access known? - what kind of water is it? - how do I get there? Yumo.to brings together 19,652 onsens across all 47 prefectures into one searchable map. What you can do with it: - search by place or prefecture - filter by tattoo policy - check price, opening hours, access, and parking - view water data when available - trace listings back to their sources The hard part was the data. There is no single clean nationwide onsen database, so I had to merge national datasets, local open data, OSM, and water-chemistry sources, then deduplicate the results and keep source attribution on each entry. I’d love feedback on: - search quality - missing or incorrect listings - which filters or trip-planning features would make this more useful Thanks for taking a look, arigato :)