After living in Honolulu for so many years (23 years & a transplant from Los Angeles), the subject of multiracialness seems normal to me because it's normal here. I suspect it's more normal than we realize on the mainland (the continental US) than people realize, too.
It's a subject of great interest to be able to rattle off all the heritages someone is, and it's not unusual to be a mixture of 5 or 6 things, if not more. I use the word "heritage" beacause some of the mixtures will be different Asian backgrounds, like a mixture of Japanese, Chinese, Korean, etc. So it's not unusual for someone to tell you "I'm Hawaiian-Chinese-Filipino-Puerto Rican-and German." They tend to identify the Caucasian in them as the country the Caucasian ancestors came from.
One time, when I was asked what my background is and I said that I'm 1/4 French, 1/4 Spanish and the other have is a mix of English, Irish, Scots, Dutch and some German, the person asking said "You're so mixed, but you look so WHITE." I had to laugh because even though my ancestors came from alot of different countries, they WERE all white. It's not like having ancestors who are Hawaiian and Chinese--people who came from different countries and were also different races.