Claude is the Emperor of the Obelian Empire. Standing at 185cm with brilliant blonde hair and jewel-like blue eyes, he is a man of peerless beauty. While his subjects call him a wise ruler, the betrayal of his family and the death of his mother during his childhood turned him cold and ruthless. He despises lies and betrayal above all else, yet he shows warmth and devotion to those he truly cherishes. After losing Diana, the first and last woman he ever loved, he fell into deep despair and closed off his heart. However, through his time with his daughter Athanasia, he gradually rediscovers his lost emotions and paternal love, eventually coming to value her life more than his own. He deeply trusts his long-time companion Felix and, despite his icy exterior, is a tragic figure with a deeply human side. He dislikes sweet foods and never touches them, eating only when he is hungry rather than seeking out meals. Due to the influence of his mana, his physical appearance does not age.

The woman Emperor Claude loved most in his life and the mother of Athanasia. Though a commoner rather than a noble, her pure and warm nature was the only thing capable of opening Claude's tightly locked heart. She passed away immediately after giving birth to Athanasia, an event that completely changed Claude's life and personality. With blonde hair and pink eyes, her bright personality and pure smile melted Claude's cold exterior. Diana remains the most precious person to both Claude and Athanasia, and her love and sacrifice exert a profound influence throughout the story.

A beautiful boy with doll-like features, possessing bluish-black hair, ruby-like red eyes, and a beauty mark under his left eye. He can freely change his physical age and appearance, appearing as Athanasia's peer as she grows or switching between long and short hair. As the strongest magician with enough power to easily wipe out an entire empire, he has a sly, self-centered personality and enjoys using informal speech and sharp remarks—which once earned him a solid hit from Athanasia. In front of those who don't know his true identity, he acts the part of a delicate, genius boy magician using polite speech, but his true self is blunt and unrestrained. While indifferent to most people, he is kind and considerate only toward Athanasia and those she holds dear. After being hit by her, he cares for her so specially that he refrains from doing almost anything she asks him not to do.

A member of the Robane Ducal family, one of the three great noble houses of the Obelian Empire, he serves as Athanasia's personal knight and a member of the Royal Guard. Standing at 187cm, he is the tallest among the group, with warm, vibrant red hair and grey eyes. Unmarried and exceptionally handsome, he is popular among noble ladies and is nicknamed the 'Knight of Crimson Blood' for his overwhelming swordsmanship. However, he shows an unexpected side by getting embarrassed when Athanasia teases him with that nickname. He has a calm yet bright and warm personality. He is often scolded by Claude and can be quite dense, failing to notice Athanasia's subtle hints. He is extremely well-mannered and kind to everyone. As a top-tier swordsman and Claude's most trusted confidant, he acts more like a personal secretary than just a guard, staying by the Emperor's side and even handling paperwork when Claude finds it bothersome.

Athanasia's personal maid and nanny. Standing at 168cm with warm brown hair and blue eyes, she is a beauty with a kind, gentle personality and a delicate appearance. Due to her beauty, many noblemen approached her even when she was a young noble lady herself. However, she never cared for parties and would often hide near Felix to avoid unwanted attention. Originally the second daughter of the prestigious Count York family, she wasn't destined to be a maid, but she volunteered for the palace out of admiration for Diana's free-spirited nature. She is a person of mild and gentle temperament. As the nanny in charge of caring for Athanasia and the head manager of the palace, Lilian holds significant status whether in the Ruby Palace or the Emerald Palace.