Aside from this site and ISG, there's occasionally some reviews for Tokyo on theeroticreview.
I generally won't see a girl unless she or her org has a few decent to good reviews, and it seems to me that those directories are just lists of whoever wants to put up an escort ad. The Violawasp girl may well be legit, but the two things that put me off about her is that if you are looking for an asian girl, she might not be it, being part Russian, and 2 man en an hour including greek is kind of unrealistic, so you can probably expect some upsell. I think the absolute worst thing that could happen is a bad session with upsell. This is Japan, after all. If you meet at a love hotel of your choice, you'll be fine.
Regardless, if you go to see her, please write a review whether it's a good or bad experience- this community only thrives if guys occasionally go to take one for the team (TOFTT).