I just saw "Miyuki Chan in Wonderland" and get a crazy idea. Imagine a girl being swallowed to the strange realm, just like in Carrol's story. But this one is much more perverted than original and our girl has to face many dangerous and erotic events before she'll come back to her world (if she'll back, of course).
I don't know if I'm good enough to play it as a game master (probably not), but if there's someone who might like to play it with me as this girl, I will gladly play.
There is also different idea, with more than only one girl, but I think for now I'd stay with one character.