Driving a mini van in Kyushu

Hi! I intend to rent a car for a family of 7 adults in November for a week to drive around Kyushu (Fukuoka to Nagasaki, Saga, Kumamoto, Miyazaki, Oita). A car for 7 persons & 7 luggages - I thought of the Toyota Hiace.

I would like to ask a few question for your kind advise:-
1. Would the roads be too narrow / dangerous for a Toyota Hiace? E.g. if we were to drive up to Mt. Aso or to Takachiho Gorge - is the road wide enough for Toyota Hiace?
2. Is it hard to park in hotel basements with a Toyota Hiace?
3. Or if you do have another good recommendation of car that will fit us 7 persons & luggages, that'll be great.
4. If anyone has great drive itinerary for us as well, please feel free to suggest!

Appreciate someone's help and advise here. Thank you so much!

Driving a van around will be no problem. All the locations you have mentioned have much larger 45 seater buses travel through and to them.

You may have issues with certain car parks in hotels. But that is something that can be discussed when booking hotels. Many families in Japan only have a large van like a Hiace as their one and only vehicle. And they go on family trips, so their must be ample car accommodations out there also.

Do note that some of the roads will be very narrow.

As Hakata says, coaches get up and down those roads, but in some places the road itself is not much wider than a big coach, so (I don't know where you're from) you may find yourself driving slowly up the narrow bits and breathing in from time to time as you squeeze through gaps.

Even on the more remote roads, there is often a convex mirror on a post on road corners, so you can see if anything is coming in the opposite direction. They are a massive help.

I'm from a big city, and don't drive a car regularly, so I must admit that driving in rural Kyushu took a lot of concentration for me, and I didn't really get to see much of the scenery as my eyes were glued to the road ahead, but it was fine. Remember that journeys may take a while on the rural roads, and allow plenty of time. Other than that, if you're a reasonably confident driver I'm sure you'll be fine.

I know HIACE well drived already over 100,000 km total.

1)
No worry also many TAXI companies using.
Only Wheel base a bit extend 500mm longer but driving feel no big different.
Be careful when tight corner and parking.
http://kurumanomenkyo.com/wp-content/uploads/2014/01/48909359134acc196...

Open Google map and use street view.
2.7L gasoline engine is powerful and torqueful.
(gas : regular/no need high-octane "high-oc" in JP)
2WD car enough. (no need 4WD)

2)
Depends on hotel parking space.
HIACE Grand Cabin is maximum grade body size longest and tallest about 5400mm and 2400mm.
Most urban city(mid town) hotels cannot accept.
So ask first before book.

3)
Basically No if members all adult.
Only "Nissan NV350 CARAVAN" no big different as spec of HIACE.
https://nissan-rentacar.com/carlineup-rates/car/108/
If childrens with 7 or 8 seats car may enough.
(depends on luggage size and amount)

HIACE also have 9 seats car as "VAN(commercial vhiecle)" type exist
but rear seats are not so comfortable than Wagon(passenger vhiecle).
http://car-moby.jp/49887

Thank you all for your advise.

Would you have any other recommendation of a good 8 seater car plus boot space? I can also explore those then.

Cheers!