Driving to Kurokawa in December

I am planning a trip to Kyushu during 10dec-18dec. there is a travel party of 5adult + 1 3-yo kid. As we are getting the 7 days JR Pass, we are travelling extensively using the JR train routes, however we would like to visit Kurokawa Onsen.

The plan is to rent a 2 days car rental, travel from:-
Day 1: Fukuoka - Hita - Beppu/Yufuin - Kurokawa Onsen (overnight)
Day 2: Kurokawa - Mt Aso - Kumamoto (car return)

However, from the kurokawa ryokan website, it seems that it would snow in winter. I was wondering, would it be super dangerous to drive in december with icy/snowy road? Or it would be okay with slow driving and studless snow tires equipped?

The probability of snow in Kurokawa is rather low in December, especially in early December. But it is possible.

I generally do not recommend winter driving to people not experienced with driving under winter conditions. It can be very dangerous, especially in a mountainous terrain like around Kurokawa.

Thank you Uji for the info. Other thank driving, what would you recommend to take if i were to stick to the above itinerary? Can i be able to make it using JR Pass or would it be too rush?

Agree with Uji that mountain winter driving might be tough if you had to chain up.
We visited Kurokawa by way of Kyusanko bus via Kumamoto.
Double check current times.

http://www.japan-guide.com/forum/quereadisplay.html?0+94185

You could also take train from Fukuoka to Kumamoto to Aso Station then transfer to Kurokawa bus, checking that the transfer times meshed.

Also don't know if it applies but there is a regional Kyushu Rail Pass for North Kyushu you could use.
http://www.japan-guide.com/e/e2361_05.html

Have fun