That Moment When Your Main Character Switches Nationalities--and Gender

So, ten thousand words into my next novel and my main character up and decides to have a sex change. No, not in the novel. She's not a transvestite. She just decided the story would best be told by a male. A Japanese American male.

Two reasons:

1. There are not nearly enough Japanese main characters in contemporary novels. Certainly, the Japanese characters I've seen are usually the side kicks, if you will. They don't typically have main roles and they usually get portrayed as over-the-top, stereotypical, science-geek, martial artsnerds. But guess what? There are hot Asian males out there with rippling pectorals and not a pocket protector in sight. Enough said.

Yeah, that was one and two. Hot guy of an otherwise, underrepresented descent.

All this means is that I now have a whole slew of research to do before continuing my novel. Enough said.

But, before I go, I do want to say one thing. As a young child, I grew up the minority. In my neighborhoods, European Americans (because I hate the term white as it describes nothing beyond my blonde hair and blue eyes and doesn't differentiate between my fellow EA's with black hair and brown eyes and olive skin) were not prevalent. Instead, I played with kids from vast and varied backgrounds and loved the diversity. 

I guess that's why I want to make sure my novels are not white-washed.

Thoughts? Opinions? Suggestions? Cultural information that I could use when writing?