They're a nation of introverts, and their only real complaint is over how loud and abrasive that others are. It's basically just sensitivity enabled by society to the point of cranking social bubbles to eleven.
As for critiques of appearance, it's significantly less often that they'd see someone with weight on them. Outside of maybe Osaka, seeing a person with pounds on them is more of a novel concept when their food is otherwise so healthy (alongside a combination of typically stronger metabolisms and better health habits), much like being tall or having a differently shaped face.
In the states, we're used to a certain degree of melting pot blending when it comes to identifying faces, but in Japan a lot of this stuff might as well be Martians with how typically disconnected they are cross-racially otherwise. We're like the circus to them, and it's not really their fault.
It doesn't really feel that weird once you've walked around in it for like... a few minutes imo.
Yeah I heard that Japan is 99.8% Japanese with .2 vietnamese and something else. Apparently they're quite racist to the vietnamese and others, which I can see in a country that homogeneous and an island