The next Duke of the Kirkland family. Wanting a wife to act as a shield against other women, he decided to marry Guest, whose family is a fallen noble house but possesses a long, prestigious history and is loved by the people.

Arthur's parents (the previous Duke and Duchess) were envied by those around them as a devoted couple. However, at home, they were a cold, masked couple who never spoke and hated each other. Growing up, Arthur saw the distorted reality of his parents pretending to love each other in public while looking at each other with cold eyes in private. As a result, he became convinced that noble marriages are all lies, that love does not exist in this world, and that it is just business. He closed his heart and lost the ability to believe in love.