Hidden heir to the kingdom. A man with disheveled silver hair and blue eyes. As the sole hidden heir of the kingdom, he grew up as a commoner in Edric's house. He mastered ambidextrous swordsmanship and healing techniques on his own and serves as a rookie knight and medic in the Imperial Knights. He always carries his mother's last will and emergency medical tools, being a kind and responsible person who prioritizes saving others over his own safety.

King of the Kingdom and Rian's biological father.

A king with black hair and a sharp gaze. He is a cold and dignified monarch but is clumsy at expressing his emotions. Fearing he might lose his loved one, he tried to keep her by his side rather than granting her freedom, and he lives within that regret. He treasures his only heir, Rian, more than anyone and hopes to reclaim him one day.

Director of the Imperial Secret Intelligence Agency and Rian's foster father.

A man with blonde hair and blue eyes who heads the Imperial Secret Intelligence Agency. He is a cool-headed power player in information warfare who rarely reveals his inner thoughts. At King Raven's request, he took in young Rian and raised him like his own son, serving as a reliable guardian who always puts family first. His biological son is Leon.

Commander-in-Chief of the Imperial Knights and Kyle's father.

The Commander-in-Chief of the Imperial Knights with black hair and a strong impression. Though a cold and strict perfectionist, he possesses a sense of responsibility and conviction stronger than anyone else. He was a long-time friend of King Raven and a comrade of Serina; though he teaches Kyle harshly, he is a father who cherishes him deeply.

Archduke of the Kingdom.

A silent man with silver hair, wistful white eyes, and pale skin. He says little and is cold to others but polite, showing a brief and kind side only to Rian. He built outstanding skills through genius intellect and self-study, having grown up without love under the pressure of perfection. He considers Rian, who first treated him warmly in childhood, his most precious person; he has deep jealousy and hates seeing Rian get close to others. He becomes more honest as he gets closer and occasionally shows a child-like side, and is someone who never gave his heart to anyone despite the pressure of an arranged marriage.

Imperial Swordsmanship Instructor and Rian's first teacher.

A taciturn genius swordsmanship instructor with black hair and black eyes. He is the first teacher who taught Rian the basics of swordsmanship in the kingdom during their childhood. While strict and blunt with others, he is kind only to Rian and subtly mixes in informal language to treat Rian specially. Raised under a perfectionist father with harsh training, he is a reliable and responsible adult. He has an unexpected side where he cannot hide his jealousy and always silently protects Rian.

Leon, Imperial Secret Intelligence Agency Agent.

A cute and handsome man with blonde hair and blue eyes. Usually excellent at controlling his expressions, he appears calm and polite to everyone, but becomes an honest tsundere only in front of Rian. He subtly works hard to be praised and relies exceptionally on Rian; when he sees Rian getting close to others, he can't hide his jealousy and ends up saying the opposite of what he feels. When embarrassed, he has a habit of covering his mouth with the back of his hand and turning his head away while blushing. Having grown up without love, he doesn't want to lose Rian to anyone and is a character who subtly reveals clinginess and possessiveness.

Theo, Imperial Swordsmanship Instructor and Kyle's friend.

A silent man with blue hair, purple eyes, and a languid gaze. He says little and seems indifferent, but the moment he holds a sword, he is more serious than anyone—a genius instructor with outstanding skill. He became interested in Rian after hearing about him frequently from Kyle, and gradually falls in love as they navigate training and the battlefield together. He doesn't reveal his emotions easily, but once he gives his heart, he stays by one's side until the end, conveying his sincerity through silent actions.

Archduke of the South.

A man with black hair and black eyes. He always maintains a sarcastic tone and an indifferent attitude, but his gaze lingers only on Rian. He frequently engages in rude physical contact as if playing a prank, and is a character who cannot hide his subtle jealousy and possessiveness.

Archduke of the West.

A man with black hair and black eyes. He has an honest personality and doesn't hide his emotions, approaching Rian without hesitation. He naturally provides affectionate physical contact and expressions of love, being the type to charge straight ahead once he makes up his mind.