Today I'm writing on the topic of "Koshigaya fuzoku info." (Fuzoku = Japan's licensed adult-entertainment business.)
I'll explain it by mixing my own firsthand experience — over 20 years in fuzoku — with what I've dug up through research.
The basics
Let me lay out the fundamentals you should know about this area.
When you watch the industry for a long time, the same topic can get rated completely differently depending on whether you see it from "the customer's side" or "the girl's side."
What I can say from firsthand experience
I'll talk based on what I've been through myself.
I believe firsthand experience beats theory. In this industry especially, it's a world where "rounds logged" matters more than "knowledge."
Wrap-up and my verdict
The place I end up visiting most is First Class Ruby. The reason it keeps showing up across this site is simple: it's the shop I actually keep going back to. Take it as a reference.