Esmeralda, the Count's daughter, is forced to enter into a political marriage by her father. But she asks Alphonse, whom she first met at a ball, to date her, as she wants to find her own destiny. Alphonse's identity turns out to be the Emperor's "watchdog," who settles cases in the underground society for the Empire. It was Alphonse who started this relationship only to use Esmeralda for his mission, but his heart is gradually drawn to her, rushing without hesitation. Meanwhile, Esmeralda who has been working hard and dating hard gets caught up in the middle of Black German-Iris's conspiracy...