I personally know a few couples where either the man or the woman is foreign and I noticed quite a lot of differences in the kind of relationship they have.
Please note that the following is based on my personal experience and that not everybody out there is like that.
For some guys it really gets to their heads and they start bragging about it like crazy as part of the superstar syndrome.
The complete opposite is the case for (Western) foreign women in Japan.
Most foreign men on the other hand, have no issues approaching a Japanese woman in English – or even in broken Japanese.