Where to meet Japanese girls?

[ifignow]

 I'm stuck in Tokyo until January 13th, visiting family. Is there a
place in Tokyo where I can meet Japanese girls under respectable
circumstances? I went to Roppongi tonight but it was a traumatizing
experience, as there were almost no Westerners, aggressive black pimps
trying to pull you into shady clubs, and slimy Chinese prostitutes all over
the place. I'd prefer some place where the music is not deafening and I can
meet people who are not prostitutes or criminals.  I'm looking for
constructive advice here, not accusations that I am naive or arrogant.