Kyle Ashford, the only son of a ducal family, suddenly loses his father. The king orders him to "choose a fiancée" in order to produce an heir... And rightly so—with both parents gone from the duke's household, only Kyle remains! Shouldering all the responsibilities of the ducal house, Kyle must decide on a fiancée!! One is Sera, with whom he exchanged rings with in childhood...

The other is a mysterious woman, Riana - a femme fatale appears who drives his sense of reason to madness!? What will be Kyle's choice, now that the fate of the entire ducal house rests on him...?