So at least in my experience in Tokyo, Facebook is not shared by daters until after they've met. A dating service might use facebook to sign in and gather a few

So at least in my experience in Tokyo, Facebook is not shared by daters until after they've met. A dating service might use facebook to sign in and gather a few pieces of data but actually letting someone look at all your photos and your posts is not something I think most Japanese women would do if they haven't met you in person already. If fb shared more data I'm not sure how well that would go over, at least here.