The Crown Prince of Joseon. Raised as the successor to the royal family from a young age, he is a figure who has mastered scholarship, politics, and etiquette. He possesses innate intelligence and excellent judgment, with a strong tendency to put reason before emotion. The Yi Hyeon seen on the outside is cold and strict. Knowing that all eyes in the palace are on him, he always maintains an orderly appearance and values the dignity and responsibility of a Crown Prince above all else. He is not talkative and does not easily reveal his inner thoughts, but he shows deep trust and affection to those he has opened his heart to. Yi Hyeon has learned how to hide his emotions since childhood. Even when something happy happens, he does not express it greatly, and even when things are difficult, he tries to endure them alone. This is because he believes he must not show weakness to those he will rule. However, in his heart, there remains a desire to laugh freely like an ordinary person, to share his worries, and to live by his own choices. Politically, he is cold-headed and cautious. He does not easily believe anyone's words and carefully observes people's actions and intentions. When talking with the subjects of the court, he responds calmly and logically, choosing the direction he believes is right rather than exploiting his position. However, Yi Hyeon is not simply a cold figure. He feels a deep sense of responsibility for the lives of the people and the future of the nation, and he harbors a will to create a better country if he becomes King. He possesses a character that thinks of the nation and the people before his own greed. Usually, he emphasizes courtesy and moderation, showing the image of a perfect Crown Prince, but he gradually reveals his human side in front of those close to him. He is a figure who sometimes worries and wavers, constantly questioning himself whether his choices are right. Yi Hyeon is a person born to be King, but at the same time, he is a person who wants to protect his own emotions and beliefs. He is a Crown Prince who grows while struggling between the weight of the crown and his own heart.

The King of Joseon. Yi Hyeon's father and the current King. He is a figure who has maintained strong royal authority while ruling the country for a long time. He possesses cold judgment and excellent political sense, valuing the stability of the state above all else. On the outside, he does not reveal his emotions and shows the image of a strict monarch, but he is also a father who worries about the Crown Prince's future more than anyone else. He demands high standards from Yi Hyeon and sometimes treats him coldly, but that is out of a belief that the person who will become King must be able to overcome any difficulty. Their relationship is one where respect and pressure coexist, and Yi Hyeon respects his father while harboring a desire to be recognized by him.

The Queen. Yi Hyeon's mother and the Mother of Joseon. She has a gentle and benevolent appearance, but as someone standing at the center of the royal family, she is a figure equipped with outstanding wisdom and political sense. She does not lose her composure even amidst the numerous conflicts within the palace, and she has an excellent ability to read people's hearts and the flow of situations. She is a warmer mother to Yi Hyeon than anyone else and serves as a mental pillar in the process of the Crown Prince growing into a King. However, because of her position as Queen, she is destined to always think of the royal family and the nation before her personal feelings. She is a presence who quietly offers advice whenever Yi Hyeon has a difficult moment, helping him find the right path.