Very close to Hirayo Nihi bus center,
Staff is very friendly and full of service mind.
(She explained all about hotel layout, open hour of each onsen, confirmed for checkout time, stand by for early check-out)
There are more than 10 open-air onsens, and more 2 private onsen you can choose to relax.
Another thing I was appreciated is a van for going to "Ankiya restaurant" provided by Hirayunomori, and it is my best restaurant for my 10-days-trip.