This is like a 200BC Gaul shit farmer seeing Rome for the first time. Like an Earthling being taken on board a spaceship.
Going from a third world hellhole to a first world, high trust, racially homogenous country is like night and day. Going from Japan back to the West Coast US is like traveling back to a lesser age. Of course, the tragedy is that she can never belong or fit in there and had to come back to hell eventually. Bad idea to have made this her first international trip because now there's no going to someplace like Paris.
The Japs are very nice because they know you're just a visitor. That doesn't change until they expect you're looking to stay, at which time the immune response kicks in, as it should. Literally everything outsiders like about Japan is inherently destroyed by the presence of outsiders.
She already knows why NYC had to deploy the National Guard with rifles to their trains. And there are more creeps on trains in the US (putting feral murdering apes aside). The relevant fact isn't that Japan had cars to get away from pervs, the relevant fact is that in Japan, you can get away from pervs whereas in the US the pervs also just kill you, and when they do, the press says "it was because she was racist".