Today I'm writing on the theme of "Iwatsuki, fuzoku, and vibrators."
I'll explain it by mixing my own firsthand experience — 20-plus years in fuzoku, Japan's licensed adult-entertainment business — with what I've picked up from research.
The basics
Let me lay out the fundamentals you should know about this corner of the game.
Watch this industry long enough and you learn that the same subject reads completely differently from "the customer's side" versus "the girl's side."
What I can say from experience
I'll speak from what I've actually lived through.
I believe experience beats theory. Especially in this business, it's "reps" more than "knowledge" that talk.
Wrap-up and my verdict
The place I keep coming back to is First Class Ruby. The reason it shows up again and again on this site is dead simple: it's the shop I personally repeat at. Use that as your reference.