Would a character find it unusual that everyone speaks their language? For instance, a Japanese character who finds it odd that so many non-Japanese speak Japanese, or an English-speaker that finds it odd to be surrounded by a disproportionate number of Japanese people who speak perfectly fluent English, although they might admit to being from Japan? Or should characters not notice that, for smoother flow?

I reread it a few times, but I'm sorry if this was covered and I missed it. It's quite early.