Jeanne Hedge wrote:

I gotta questions.

When I first started perusing Ranma 1/2 fanfic a while ago, it quickly
became apparent that many of them are "lemons" (what this says about the
Ranma 1/2 readership I can't say).  It also became apparent what a
"lemon" is.

But this raises the question:

Why are lemons called lemons?

I don't know why, but I would guess that it has something to do with a very
(in)famous and popular OAV(?) series by the name of "Cream Lemon" (or "Creme
Lemon" - I've seen it spelled both ways).  I've not seen it, but from what
I've been told every episode spends major amounts of time on sex scenes.

Jeanne Hedge

I was wondering if it had a similarity to the calling of a car a 
"lemon". I heard the term, but it was years ago. I think it was one of 
those cars that are bought cheap but aren't what they're advertised to 
be. So are lemons "cheap"? I'd like to know why they're called lemons (I 
mean for sure) too...

"Hino Rei"