It varies from night to night and what time you are around there honestly. None of these women are all that attractive but some nights/times some better looking ones. Of course looks do not equal performance and in any case without having tried any of them I can't say "look for this one" or "the better ones are by this place". If you are really curious just go down that area a few nights and see if you find something you want.
In Tokyo: Nippori Station and Akabane Stations in Tokyo at night for freelancers. Near Don Quixote in Shin Okubo for more freelancers. --back streets near there.
International Sex Guide has information about Osaka.