Foreigners in Japan: how do you deal with idiots accusing you of “pretending to be Japanese”?

I’ve dealt with this way too many times as a westerner living in japan, and I’ve seen other foreigners in Japan get the same nonsense. It’s usually random white people: usually the “woke police,” sometimes MAGA, trying to gatekeep matcha or accuse you of “pretending to be Japanese” when you’re literally just living your life in the country you moved to. The culture isn’t even theirs to gatekeep.

How do you respond when someone accuses you of “acting Japanese” or “pretending to be Japanese”?