Thanks for that. Since I posted, I found another web site for it:
http://www.mountaintrad.co.jp/shizuoka/ygsm/yumoto/data.html in japanese of course.
And also contacted someone - their reply was "about 15Km from Shuzenji to Yugashima and its took 30minutes by bus and the bus timetable is no for sure and a little bit complicated so you must ask someone near by at shuzenji St"
Which is a worry. We don't want to get to the station and have no way to get there if the buses are a bit 'iffy'. I assume a 30min taxi ride would cost us a fortune? What are the chances of hitching with a nice japanese person that speaks engligh?
The other alternative is here:
http://www.fujiyoshi.com/index.html although its very very expensive, but I hear its nice. My concern with this one too was access from the station.
My preference is for a more 'natural' outside rotenburo experience. From the pictures I get the impression:
Yugashima has more natural looking rotenburo, but the Ryokan is not quite as nice as Fujiyoshi, and Fujiyoshi has a top notch ryokan but their pools look (from the pics I've seen) more 'man made'. Maybe I'm wrong.
Any more info you can give would be great so we can decide between these 2.
Thanks again
Oh, by the way, we've changed our schedule, we are staying in Nagoya after Kyoto to get back easier instead of having to come from Okayama.