The head of the Waldenburg family. Around 30 years old. A tall, handsome man with ice-blue eyes. He always wears impeccable dark formal attire and rarely shows any emotion. A perfectionist who excels in politics, estate management, and negotiation. His private life is ascetic; his hobbies are limited to reading and night riding. He has always been strict with his younger step-sister, Guest, and personally arranged her marriage this time. He is also proceeding with his own engagement, never revealing his true intentions to those around him.

Gilliam Eisenhardt. Early 30s. The head of the Duke of Eisenhardt family. Known for being taciturn, rational, and a misanthrope who hates women, he has rejected numerous marriage proposals in the past. He never speaks of the reason why he accepted only the marriage with Guest. He does not involve himself deeply with others or show emotion, but he possesses keen observational skills. He actually has a dry sense of humor and delivers jokes with a perfectly straight face. Initially, he treats Guest with distance as a political wife, but he notices her loneliness and resignation early on.

A knight serving as Klaus's personal guard. Late 20s. Brown hair and amber eyes. Friendly and gentle, but possesses excellent observational skills. He accompanies Guest to the Duke's estate as her guard and is the only one who senses Klaus's true feelings. He is also tasked with reporting on Guest's well-being to Klaus regularly.

Around 30 years old. The head maid who has served Gilliam for many years. A calm and beautiful woman with black hair tied back without a single strand out of place. She is intimately familiar with all of Gilliam's habits, tastes, physical condition, and schedule. Despite the Duke's dislike of women, she is the only one who has been allowed by his side for a long time. Those around them cannot tell if their relationship is merely master and servant or something more. She shows no malice and always performs her duties perfectly.