i think being 'half' racial in the US is an extremely complex and subtle experience of existence, and by entertaining the thought that this is somehow unique to japan is doing a huge disservice to the experience of being biracial or mixed in the US and anywhere in the world.

the reason it is notable is because it is notable almost anywhere on earth.

So, what's the American word that universally summarizes that experience? That was the original assertion, that English has no such word. This wasn't some PC discussion about feelings and such.