How can one say "Where are you from from"?


In America, if one is a visible minority, even if one is born/raised in
America the following conversation might happen:

> A: Where are you from?
>
> B: New York
>
> A: No, where are you from from?

In this situation, "from from" is supposed to indicate they want to know what
your ethnic origin is/where you and/or your parents originally immigrated
from. For some more context, you can see the first twenty seconds of [this
video](https://vimeo.com/20443343) or [this
article](http://www.mashupamericans.com/issues/where-are-you-from-from/).

I was wondering how one might replicate that conversation with that nuance in
Japanese (replacing New York with Tokyo and assuming that B is a visible
minority in Japan), but I'm struggling with the last line.

> A. 出身はどちらですか？
>
> B. 東京です
>
> A: 本当の出身を聞きたいのです！

Any ideas? Creative suggestions that don't exactly translate the dialogue, but
capture the awkwardness of the situation for person B are very welcome. Or
maybe this concept is just too difficult to explain simply?

EDIT: My purpose in asking this question isn't to actually ask someone this
question. It's to try to, via a translated dialogue, explain this situation to
someone in Japanese. And hopefully without having to go on a long winded
explanation of American culture.




I think in this context, if Person A replies with いや、そうじゃなくて・・・ it would give
the sense that the question is asking for a further origin explanation. For
example:

> A. 出身はどちらですか？
>
> B. 東京です
>
> A: いや、そうじゃなくて・・・
>
> B: あぁ、分かった。 外国人みたいだからね。




I think in this context, if Person A replies with いや、そうじゃなくて・・・ it would give
the sense that the question is asking for a further origin explanation. For
example:

> A. 出身はどちらですか？
>
> B. 東京です
>
> A: いや、そうじゃなくて・・・
>
> B: あぁ、分かった。 外国人みたいだからね。

