"Denma in Kawaguchi, and why it's popular" — denma being the electric massage wand that's a fuzoku staple — some people hear that and know exactly what it means, and some don't.
I'm 42 and still out there working the floor of this world, so I'll lay it out from a real-world point of view.
Why this topic matters
Information about fuzoku — Japan's licensed adult-entertainment business — is surprisingly disorganized. Beginners especially tend to have no idea where to even start looking.
What this actually means
In one line: whether you know it or not changes the quality of the experience.
I'm putting the essence of 20 years of accumulated knowledge right here.
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.