I am in the mountains around Mt Fuji now (that is a massive area, I am not significantly doxing myself folks, don't worry) and it is pretty nice, but I definitely wouldn't mind more towards Hokkaido. I love the cold though, I will take a snowstorm over Tokyo summer any day.
My annual check-up revealed some health issues, which made me change my lifestyle a lot. I can clearly see how it can promote longevity.
Btw, which inaka would you consider? Looking at the summers this year, I feel the northern parts would still be livable in the future.
I am in the mountains around Mt Fuji now (that is a massive area, I am not significantly doxing myself folks, don't worry) and it is pretty nice, but I definitely wouldn't mind more towards Hokkaido. I love the cold though, I will take a snowstorm over Tokyo summer any day.