Show HN: Yumo.to, a map of 19,652 onsens in Japan

vansbel · 2026-03-08T19:27:19.000Z 1772998039

This is a fantastic resource! I love the map-first approach for niche discovery. Since you mentioned you're looking for feedback on how to make it more useful, I actually ran Yumo.to through an AI landing page 'roast' to see if there were any clarity or conversion gaps for first-time visitors.

One quick takeaway: visitors might initially miss the 'tattoo-friendly' filter, which is a huge USP for international travelers. Helping that stand out could really drive engagement. Happy to share the full prioritized improvement plan if you're interested!

You can also check it out to start. Use this https://website-roast.lovable.app/ :)

katagamistudio · 2026-03-09T03:29:01.000Z 1773026941

Thank you so much, and you are right about the filter. I'm gonna change that asap

katagamistudio · 2026-03-08T03:29:58.000Z 1772940598

Happy to answer questions about the data pipeline. The hardest part was that there isn’t one clean nationwide onsen database, so I had to merge official national data, local open data, scientific datasets, and community sources, then deduplicate them and keep source attribution on each entry. It's also quite hard to find proper websites for each entries

idiocrat · 2026-03-08T03:52:08.000Z 1772941928

For me the dots appear as white on a grey terrain. Impossible to see.

Win Firefox 148.

katagamistudio · 2026-03-08T03:54:35.000Z 1772942075

Not white on blue? I'll check why it appears grey!

genxy · 2026-03-08T06:30:29.000Z 1772951429

https://en.wikipedia.org/wiki/Onsen

A girlfriend of mine (white girl) knew Japanese and would work at a hotspring in the US during the summer between semesters in college. It was her job to tell old Japanese men that the hotspring was not clothing optional.

I see lots of listing that appear to have no data or links. Or if they have links in the description, they are not clickable.

I am not seeing a filter. Or links back to sources, or an icon with the type of source. No offense, but this looks like a good 10% start.

katagamistudio · 2026-03-08T06:53:08.000Z 1772952788

Thanks! For now you can only filter by tattoo policies (tapping the color circles) or you can also filter by town or prefecture using the search feature

I'm adding more data, it takes a while to ingest and process since there's 19000+ listings. it should be way more complete in the next few days