Fukuoka (Hakata) to Kurokawa Onsen

Hello
(First of all, sorry for my english)
I am looking for the most convenient way to go from Fukuoka (Hakata station) to Kurokawa Onsen.

I have read in this forum that there is a direct bus that make the travel in 3 hours. I have this link to a timetable and i don't understand it

http://www.kyusanko.co.jp/sankobus/change/timetable.html

Is this the timetable for the direct bus? In this case, what is the meaning of this "（乗換)"?

Another question. I am planning an excursion to Mt Aso in the tourist bus. I am thinking on taking it in Kurokawa Onsen to Mt Aso and then return from Mt Aso to Kurokawa Onsen in other bus. Is it posible?

Thanks in advance!

I have read in this forum that there is a direct bus that make the travel in 3 hours
A direct bus is run by Nishitetsu and there're only 2 services a day.
8:56(Hakata)-11:58(Kurokawa)
13:36(Hakata)-16:38(Kurokawa)
And you need to book a seat in advance.
http://www.nishitetsu.co.jp/bus/highway/gb/guide/kurokawa.ht...