I have kept in touch with many Japanese and find that within Japan, there are many prejudices against Japanese women. For example, many Japanese women cannot work past the age of thirty whether or not they're married. There seems to be a basic disrespect for women in Japan - maybe like USA in the late fifties. I like both Japanese men and women as people as well as their culture. While you just have to accept some general things about their culture, you also have to understand that there are many different individuals who do not reflect the generalities.
Japanese people are probably the most insular people when it comes to interracial marriage.
However, dating and romance are different from marriage. I have lived in Hawaii and California and find that most Japanese-Americans in these places don't want white or other colored boyfriends. Women who were raised in Japan seem to be more daring, but don't want a marriage with a non-Japanese. I was happy to be one of their gaijin experiences. For instance, buraku people are thought to be untouchable.