Nina, the girl with eyes the color of lapis lazuli, is scouted by the second prince of Fortna, Azure, to replace priestess-princess Alisha, who died just before she was to be married off to the prince of Galgada.

Azure, who has a similar background to Nina serving as the double for the deceased prince since he was a child, finds himself drawn to Nina and promises to find a way to break off the engagement. Unfortunately, to save Azure from the king himself, Nina swears she will become the queen of Galgada and leaves Fortna before Azure can object. But the crown prince of Galgada, Sett, known for his penchant for violence, might not allow this plan to come to fruition…