Yeah hikers in Japan are mostly seniors and they are way more experienced than youngsters. Everytime I go for a hike there are the usual grandparents who hike in groups, and who overtake you on a climb with the blink of an eye. They are way fitter than most 20s years old.
Those old Japanese hikers are awesome. While we were in Japan we did the obligatory "climb Fuji at night to see the stars and the sunrise from the top".
We didn't get started as early as we hoped, so we had to push hard to reach the top in time. 100 ft from the top I collapsed with a very painful cramp in my calf. So without a word this old Japanese guy gives me this incredible 30 second massage and I limp to the top.
The sunrise? Complete letdown. Prairie sunrises are much more spectacular, and the star view is comparable. But the climb was awesome.
I did the Fuji climb a few years ago too, and this is a quite ugly mountain when you climb. But I did find that the view, looking down watching at hundred of hikers climbing with lights at night, was quite charming.
The worst bit about my first climb up Half Dome was being passed by the senior citizen couple, with walking sticks, whom I had passed an hour before...