The real secret is that they have amazing mass transit infrastructure which makes for extremely walkable cities. Only about 10% of Japanese people own a car and so they probably get way more exercise just from living day to day than the average American gets in a week.
Plus Japanese 7-11 is considered decent food. Compare to 7-11 here where any food is a combination of salt, more salt, and sugar, with maybe some protein or carbs. I imagine this quality difference expands to other establishments as well.
I think it’s the other way around. Mass transit greatly benefits from walkable cities because that means distances are shorter which in turn makes the whole system cheaper to build and operate.
Walkable cities are created by not emphasizing car infrastructure which necessitates good mass transit because people still need to get around which creates a more walkable city, etc. It’s kind of a chicken and egg situation, they’re both the cause and effect of each other in an endless cycle.
