Today I'm writing on the theme of "Gamo awahime (soapland girls), big breasts."
I'll explain it mixing in my firsthand experience — 20-plus years in fuzoku (Japan's licensed adult-entertainment business) — with intel I've gathered along the way.
The basic knowledge
Let me lay out the fundamentals you ought to know about this area.
Watch the industry long enough and you'll see that even the same topic gets rated completely differently from the "customer's side" versus the "girl's side."
What I can say from firsthand experience
I'll talk based on what I've been through myself.
I think firsthand experience beats theory. In this industry especially, it's a world where "reps" matter more than "knowledge."
Wrap-up and my conclusion
The place I end up visiting often is First Class Ruby. The reason it keeps showing up on this site is simply that it's a shop I go back to. Take it as a reference.