Aru Hi Totsuzen Do-S Ouji no Tsuma ni Narimashita

Natalia, a Count's daughter, can't bear the thought of marriage. The reason is that she can see people's emotions as colors of their aura. Her maids, while smiling, seethe red with hatred, and her gentle teachers bristle with the color of anger. Unable to trust others, Natalia botches her debutante ball and becomes a recluse. Concerned for Natalia, her younger brother Julian drags her to a ball hosted by a member of the royal family. But the overpowering mix of colors and auras makes Natalia feel sick. Suddenly, an aura flaring with red anger and black hatred appears! She's never seen an aura so dense that it completely obscures the person emitting it.

Natalia freezes, trembling as the figure approaches her. But as he draws nearer, she recognizes him as His Highness, Prince Ludwig...?!