Mixed/private onsen in Kirishima?

Hi,

Me and my girlfriend will be staying in Kagoshima next month and plan to do a day-trip to Kirishima. First we'll head to Ebino-Koen, after that Kirishima-jingu. Are there any good onsen nearby? A rotenburo would be cool and shouldn't be too expensive. As we're having accomodation in Kagoshima, there's no need for a onsen ryokan, and since we got a rental car it doesn't matter if it's off the track.

Thanks for any help, my own research hasn't be so succesful yet..

A friend of mine recommended this onsen.
Ryokojin Sansoi—·slŽR‘‘j:
3865 Takachiho, Makizono-cho, Kirishima-city, KagoshimaiŽ­Ž™“‡Œ§–Ά“‡Žs–q‰€’¬‚η•δ‚R‚W‚U‚Tj
This ryokan has 4 private roten buro which non-staying guests can use from 11:00-14:10. (You can stay till 14:55). It costs 1000 yen/per person for 45 min.
Please click "‰·ς" on the top page (Don't select English!) and click "—Ρ‚Μ’†‚Μ‘έΨ˜I“V•—˜C‚Φ" at the bottom. Then, pictures of the 4 rotenburo will appear.
http://ryokojin.com/