Trip to Sakurajima

We're planning to go to Kumamoto then head to Sakurajima. We'll arrive there at around 1 pm. The question is, after we catch a ferry to Sakurajima (do we pay for our ticket on the Sakurajima side?), should we rent a bicycle and tour the area ourselves, is it doable? Or should we tour with the sightseeing bus? And with the sightseeing bus, where can we buy a day ticket?

Also, I've read it somewhere that there's a JR Kyushu sightseeing tour for Sakurajima, does JR pass cover that?

Thanks.

We're planning to go to Kumamoto then head to Sakurajima.

I assume you mean Kagoshima.

after we catch a ferry to Sakurajima (do we pay for our ticket on the Sakurajima side?)

Yes, payment is on the Sakurajima side.

should we rent a bicycle and tour the area ourselves, is it doable?

It depends on where you want to go. If you are okay with just seeing the area around the pier, you do not even need a bicycle. But if you want to go to more distant places, you better us the buses or rent a bicycle. Joining a bus tour is another option. I think that many of them depart from the city center. It all depends on want you want to see and your preferred travel style.

And with the sightseeing bus, where can we buy a day ticket?

The information desk in Kagoshima-Chuo Station will be able to help you:
http://www.city.kagoshima.lg.jp/_1010/shimin/foreigner/foreigner-sight...

Also, I've read it somewhere that there's a JR Kyushu sightseeing tour for Sakurajima

Yes, as you can see on the link above, some of the sightseeing buses are operated by JR Kyushu.

does JR pass cover that?

I doubt it, but I am not sure.

Thanks Uji, much appreciated! I think we'll rent a bicycle instead of joining the bus tour, though I'm not sure if it's doable if we want to ride to most attraction places. We also want to visit the Onsen, will it be too hard to ride that far out?

We also want to visit the Onsen, will it be too hard to ride that far out?

Which one? Note that the famous Furusato Onsen open air bath has closed last year. There is an onsen bath near the ferry terminal, but frankly it is not very outstanding. The extremely long foot bath in the park near the ferry terminal is quite nice, though.

Ah, thanks for the info Uji. Will definitely try that foot bath.

While nothing spectacular as Uji says, the Magma Onsen baths near the ferry terminal (easy walk) is inexpensive and features red iron ore looking water and quite hot. The few times I went to it there were a lot of friendly (and some English speaking) locals who engaged us in nice conversation. Map below shows onsen and foot bath + more.

http://www.japan-guide.com/e/e4601.html