This[0] is early April, government representatives all wearing masks, a normal practice for Japan.
That's still "more culturally accepted and practiced widely", but it was far from some claims I see that "everyone is wearing masks". Everyone is wearing masks when they're sick, not every day.
EDIT: Reading the comments again, it seems that they're talking about post-COVID, so I misunderstood.
But now, and since COVID-19 became a thing (February here), "everyone is wearing masks" even when they themselves are not feeling sick.
I sometimes count them when I go out and it is about 95% of people in the streets and 100% of all the shop employees I interact with.
Of course this is mostly for the sick, but also generally in times of seasonal illness, but also yes.. this pandemic. But across this spectrum, Japanese cultural acceptance of wearing masks is much higher than even right now in the middle of covid for Americans and particularly their political leaders, to say nothing of non-pandemic mask usage. So the contrast is stark.
Here's a random article[0] I just googled (but I've seen many more speaking to this dynamic) of prevalent mask usage in Japan, written in 2017. There's some pictures there too, of Japanese people wearing masks.
[0] https://theculturetrip.com/asia/japan/articles/why-do-japane...