"Horinouchi fuzoku booking" — some people hear that and instantly get it, and some don't. (Fuzoku is Japan's licensed adult-entertainment business.)
I'm 42 and still out walking the floor of this world, so I'll lay it out from a real, on-the-ground point of view.
Why this topic matters
Information about fuzoku is surprisingly disorganized. Beginners especially tend to end up not even knowing where to start looking.
What this means in concrete terms
Put it in one line: "whether you know it or not changes the quality of the experience."
What I've written here is the essence of the knowledge I've built up over 20 years.
Last word
If you've got questions on this topic, drop a comment or hit me on social. And check out First Class Ruby while you're at it.