Furusato onsen, Sakurajima

Does one need to make a reservation for a day plan/day trip excursion to Furusato Onsen in Sakurajima? I.e., do you have to make a reservation to enter the Ryuujin Outdoor Bath, or can you go to the hotel and pay the 1,500 yen fee on the day you want?

Ive been to Furusato a few times and no reservation is required to use the baths as a day tripper. Day trippers can also use free shuttle buses from the ferry terminal that depart once per hour during the day.

http://www.furukan.co.jp/access.html

Also, the entrance fee is 1050 yen not 1500 yen. There are some meal plans that you might want to consider that include lunch at the hotel and sometimes use of a private room.

http://www.furukan.co.jp/plan_higaeri/index.html

Just a note for all, Furusato onsen is closed as of September 2012 (though it might reopen sometime in the future). We learnt this from the Tourist Information Centre in Kagoshima.

I hope they are renovating furusato onsen in Sakurajima. I went there 3 years ago and it needed an update.