Just to generalize: Asian American girls can be broken down into two groups...ones who would only date Asian guys and ones who would never date Asian guys.
The first group fit in more with their Asian background and have parents who expect them to date Asians. They enjoy having a partner who understand their cultural background (music, food, etc) and cultural views.
The second group go completely opposite...they see white guys as guys without all the cultural baggage...they're not demanding or "mama's boys". Not to mention, white guys don't have crazy Asian mother-in-laws.
Even within Asian culture, there are opinions.stereotypes. Korean girls are hot but high-maintenance. They prefer to date Chinese guys because Korean guys are seen chauvinistic and have overbearing mother-in-laws. Chinese girls are "plainer" than Korean girls but are more "gentle". (Again, these are stereotypes).
Also...IMO the perception of beauty between white and Asian guys are very different with respect to Asian girls. I have often seen mixed couples where a handsome white guy dates Asian girls who I consider to be "plain." There are some articles about how white guys look for Asian girls with "exotic" features while Asian guys don't. Of course there are exceptions...two of the most attractive Asian women I know married non-Asian guys.
Finally, the lines between races are blurring, especially in a place like Irvine. Mixed couples are going to be norm in the next 10-15 years.