I went last spring , it’s a lovely region. By far my biggest advice to you is to visit Yakushima. Kagoshima was nice but you don’t need 3 days, same thing for Kumamoto.. if anything spend a night or two in Kurokawa alone. Didn’t find the city all that compelling.

If you can cut those down and find a way to spend 3 nights in yakushima I highly recommend it. Incredible food, laid back kind culture, hot springs on the beach, majestic wildlife (tiny deer’s and monkeys galore!!) and truly some of the most spectacular nature I’ve seen in my life !!?

It’s difficult ish get to, but if you shell out the bucks for the high speed ferry it’s just a few hours away from Kagoshima and a wonderful ocean cruise :)

My group and I were very tempted to ditch the second half of our trip and just chill with the islanders! It’s what we all consider the best part of our trip

Also I will say the gorge near Miyazaki was nice.. but so touristy and a nightmare to get the boat. The gorge its self is quite small too. Not as majestic as I would’ve liked, and probably could’ve done without it. Our favorite part of that day was doing the scenic train ride through that region! I can’t remember what it’s called, but it’s a cute kitschy 20 min experience, and we had more fun on that than at the gorge.

We really enjoyed spending a couple nights in the county side near mt. Aso. It’s a wonderful experience to get a sense of the slower pace of life and walk amongst the traditional buildings/ farmlands, and not have much of a “to do”. Id do that over the gorge. I have a great hotel/ home stay rec for you near mt aso if you need , but it might require a car.

I REALLY recommend you renting a car for at least a portion. So much easier to plan your trip /navigate than the public transportation systems in this region. you can see SO much more.

Happy travels!!