Basically, making a story that takes place in Japan and I want two twin girls to be in the story. These twin girls speak Japanese but are not from Japan and I would make them, say, English if it were in the USA or Portuguese if it were in Brazil, but Japanese is only really spoken in one country. I suppose there are, however, other countries with a large Japanese-speaking population. Maybe they could be Japanese-Brazilians? Grew up with the Japanese language and all, just born and raised in Brazil and came to Japan later in life?

Well Japan has never been colonized, but you could represent a country that excerted foreign influence, maybe? Although thay relation wouldnt be as direct as - "Straight up colonized".

Thanks :)

You could make them part of a diplomatic family? Or a mission? Anything that requires you to live abroad for years, really.

Americans with one Japanese parent. Raised in the US but spoke Japanese at home.