I'd be happy to GM it. Not a system though, freeform.
I had an idea for a twisted plot but will keep that close to my chest for a bit, but I'm thinking the girls are clothed when they jump universes and naked when they arrive.
And the place they arrive has the same landscapes, hills, rivers, roads, towns and villages as the place they left; its as though they've just gone back in time. Almost. Not quite. Some incongruous things might show up. A hint of modernity here and there.
Everyone else is naked as well. Its simply a naked world. Lots of jewellery and even piercings if that's something the players would enjoy. The weather is warmer and there's a few other oddities.
However, rather strangely the nude locals also seem oddly uncomfortable being naked.
Someone called The Cardinal-General gets mentioned. A lot. People are afraid of him and do not like to discuss him. He seems to be either a military leader, a church leader, a state leader or maybe all three. Or maybe none of those.
I have a storyline bubbling about in the back of my mind but haven't ironed it out yet. I'm thinking all the players (however many there are) each play one of the modern girls. I'll tackle everyone else as NPCs. That way I can feed snippets to players via PMs for their characters to learn and reveal.
Daril - how many people do you think this premise needs?