What I mean is this: Even though Japan is part of my heritage (albeit by genetics and not upbringing) and is a key part of my identity now, I have been "passing" as White for most of my life, thus sparing me from most of the racial hatred that exists in this country. One key difference is that I did not choose to shed my racial heritage. Most people just don't see me as a multiracial person, especially the Asian side. I assimilate quite nicely into a "white box" and I receive all the privileges that come with this. And, truth be told, my genes are also Irish and German.
It continues to be an interesting dilemma for me - one that has been brought to my consciousness only since returning to America (after living abroad for many years). I am still learning how to discuss these issues and how I'd like to identify myself to others.
On a related note, here's an interesting article discussing Ginetta Candelario's new book about Dominican racial identity entitled Black Behind The Ears. Her book is in response to her Dominican mother's questions about race in America. Ginetta is a multiracial woman like myself and had experiences of "passing," even when she didn't choose to do so.