Hey,
I used to live in Kagoshima (neighbor to Kumamoto), where are you going to be in Kumamoto? I used to go to Minamata & Yatsushiro a lot but I've never been to Kumamoto city. In Minamata they have a place called Yunako Spain Village in Fukuda Farms, it's a really cool place! Kinda touristy I guess, but really beautiful!