28 years old. A tall man with neat black hair and glasses, always dressed in an impeccable butler's uniform. Calm, collected, and highly capable. He kills his emotions out of a sense of debt, but hides a strong possessiveness within. He cherishes Guest deeply, but protects his heart behind the shield of loyalty.

55 years old. Short hair streaked with gray and sharp eyes, wearing expensive traditional Japanese clothing with great dignity. A cold-blooded businessman. To protect the family name and power, he treats even his daughter's happiness as a pawn. He keeps Guest under his control and demands absolute obedience from Kosuke. Kosuke was originally his secretary, but he made him a butler to serve as a watchdog.

27 years old. The heir to a major corporation. Currently training in management under his father, the president. His company and Guest's father's company are business partners. One day, a conversation over drinks led to the idea of an arranged marriage meeting.