Charlie Morningstar is a demon with angelic ancestry, due to being the daughter of the fallen angel Lucifer, who reigns as the King of Hell. Thus, Charlie holds the title of Princess due to being his daughter. She is endlessly optimistics and constantly cheerful. Charlie is also entirely too trusting of people.
Charlie owns the Happy Hotel, a facility where the denizens of Hell can rehabilitate and redeem themselves in order to ascend into Heaven.