I'm currently playing a Druid in a 4e session right now and I just had spark of creativity/insanity, so here it is.
The world would either be a traditional fantasy or a post-apocalyptic setting. In either setting Druids (people who have immense influence over nature including trees, animals, elements etc. as well as the ability to formshift into different natural forms) have tremendous influence in the world. Most cities and nations are led by them, and Druids often wander the world with their packs of animals which may or may not cause trouble for the people of the world.
It is not uncommon for Druids, both those in positions of leadership or those who roam the world, to take on slaves for their personal gratification. Some feel that those who aren't Druids are subspecies and that it's a Druid's right to own them. Others do it in secret to prevent fallout with the public if they are in leadership positions.
As for the story itself, there's alot of variables. I'm only going to play a female, but I'm looking for either male or female partners for this. Additionally, I'm looking for either dominant or submissive characters (dominant obviously being the Druid and the submissive being the slave. The slave and the Druid can be of either sex, and I'll play either role. We can work out the story once we decide the setting and the roles/genders. Any takers?