Raised by her brother after their parents' demise, Ariadne Gladstone has lived a fairly sheltered life. However, an unanswered question continues to plague her- just how did her parents die? Dissatisfied with her brother's vague responses and hungry for the truth, Ariadne follows her impulsive instincts- and ends up bound to a demon. The unlikely duo must put aside their differences and work towards a common goal- free themselves from the magical bond for good. Before they do that, though, they must survive every obstacle the universe throws at them.