Well, some people are just looking for regular Korean girls for dating in the normal sense. That's why I was asking...
The problem with Korean services in Tokyo is that they are notoriously unsafe and the girls usually have really bad attitudes. The key areas of Tokyo for Korean girls is Nippori and Uguisudani (right next to each other on the Yamanote line).
Most of those services are 'outcall' where you meet a girl and go to a love hotel in the area. It may be possible to meet a girl on the street in those areas, but results are mixed and the quality may not be what you expect.
When I say 'unsafe', I'm refering to those ladies who provide bareback (BB) services. (No protection) On top of that, if you want one hour, the girl will stay with you until you have one pop and then she bolts out the door regardless of how much time is left on the clock. Once you get off, they're done and they would probably only stay longer with bribe of more cash.
Here is a list of Korean Delivery Health clubs that have been reviewed in the past from other sources:
Fellini - http://www.fellini0306.com/
K-girls - http://k-girls.jp/top.html
Nobless - http://nnobless.com/
Language wise, you should find a Japanese friend to help you if you cannot speak Japanese (or Korean). Some scattered reports say that some places can use minimal English, but don't expect the girls to know any English at all outside of "Hi" or "Bye".
That's all I can offer on Korean services in Tokyo for the time being. If there's anything else, I'll pass it at long as the info presents itself.