Just because it's ported to Japan, does not mean they aren't aware of its meanings in the West. Japanese people aren't an ignorant isolated tribe, they have the internet. Assuming she is completely unaware of the history of punk: Is ignorance bliss? I say no, perhaps you feel different. Meaning carries even if you're ignorant about it.
Fashion is a visual language, and it's built of signifiers and what is signified. You can't borrow a language without referring to its origins. Even if you want to wear a fashion and claim it's completely severed from the history of that fashion, that won't prevent the history from being communicated. Like your nazi example (why does everyone go to the nazis?) you should expect people to think about nazis, not think about "culturally distinct post-nazi fashion decision." And if you're miffed that people keep asking if you like nazis, maybe don't dress like that.
All that said, let's say her fashion sub-culture wasn't punk but some other expensive style. One could still critique stylistic expense in the consumer age and lack of class consciousness. But it's particularly ironic when the fashion they chose was about rejecting the polished mainstream for a diy/lo-fi/proletariat esthetic. And that's the point of my original comment:
Dressing like a punk by buying expensive designer clothing is funny.
https://images.app.goo.gl/BpVXCi9NMLvjuxNq5