Hm, just an idea and I'm wondering how many people would be interested in a RP that consisted of this plot:
A powerful magician has apprehended 3 (maybe 4 or 5) demons ( or something of the like) and has bound them to an estate. Centuries later (in the modern era) the magician finally passes away, passing everything, including the estate and the demons, unto his daughter. Being one who believes in second the chances, the daughter deviates a plan and strikes a deal with the demons. In order to be released, they would have to make someone fall in love with them. And so, depending on the number of demons, an equivalent (preferably) number of human candidates are brought in to live at the estate (how they are brought in should be decided by whoever creates the character. A message of some sort should reach the character and inform them that they are obligated to marry one of the demons at the estate. The characters could be willing and have volunteered for this, they could be forced by their parents, their current economic status, or whatever). Obviously the demons will be in human form and how the whole thing will work will be further explained if the RP idea is popular enough ;o