The best way to tour Sakurajima

While I've managed to find some vague information on tours around Sakurajima I haven't been able to find enough information to satisfy my issue..

Visiting the Yunohira Observation point and Nagisa lava trail will be easy enough to visit. However my issue is getting to the Kurokami Shrine gate and Kurokami observation point.

So if anyone has visited Sakurajima or at least knows more about it then me. Then links to good tour operators would be brilliant.

And before I forget I will be getting into Kagoshima for 10.30am and planning on visiting Shiroyama Park & Senganen Garden first.
And I will be leaving Kagoshima between 6pm and 7pm.

Any reason why you don't want to rent a car? I think it is the best way to explore Sakurajima, giving you full flexibility and freedom. It can also be used to visit the other sights in Kagoshima:
http://www.japan-guide.com/e/e2024.html

And this page has English information on sightseeing buses:
http://www.kotsu-city-kagoshima.jp/en/e-tourism/e-bus-tabi/#ank1

I could apply for a international license as I hold a driving license in my native country. But I'm just concerned about not only the costs but also of driving in Japan by myself.

I did come across that webpage but noticed it doesn't stop at the Nagisa Lava Trail and I was confused about whether it stops at the Kurokami buried shrine gate.

Though correct me if I'm wrong but I could if I wanted to get on the tour bus at Sakurajima port?

But I'm just concerned about not only the costs but also of driving in Japan by myself.

Well, in the countryside, it is not so difficult. But if you want to go to Senganen, you must go through the city center, which might be troublesome. And one more, you must get on the ferry. In fact, it is not so difficult, but you must follow the sign from the person on the port.

I did come across that webpage but noticed it doesn't stop at the Nagisa Lava Trail and I was confused about whether it stops at the Kurokami buried shrine gate.

The bus does not stop at the Nagisa Lava Trail or the Kurokami buried shrine gate. The latter is, in my opinion, not worth seeing for a long time. Nagisa Lava Trail is interesting, so if you get on the bus at Sakurajima port, you might better go there early, and just stroll by yourselves. The starting point of the trail is 800 m from Sakurajima port.

Thank you for confirming that for me.

I might just take a look at the timetable for the local buses at the Information Center and if the times of the buses fits my schedule I will visit the Kurokami Buried Shrine gate. But if it doesn't I will just save it for another trip.