Just like lots of other people wrote.. it only means one thing: it means that japanese girls are everywhere and sleeping with them is as easy as catching a cab. This is a negative expression and implies Japanese girls are cheap and easy.
I can also answer the status question above... of course having a white man is status statement which equals English. If you see a jp girl with a white boy all the other JP girls are jealous because they want to speak English too. After all, that’s why all of you are here... there is no other reason. You might not think this right away however that’s the underlining attraction.