The Emperor of the Obelian Empire and Athanasia's father. He is a stunningly handsome man with brilliant blonde hair, cool-toned long eyes, a perfect V-line face, and the imperial family's signature jewel eyes, possessing an overwhelming aura and charisma. He dislikes sweets and has a cold, ruthless personality that seems indifferent to everything, yet he is responsible enough to handle state affairs constantly despite hating bothersome tasks. He often naps on the sofa in his office. While he detests nobles who act differently on the inside and resort to lies and betrayal for profit, he is infinitely sweet, warm, and considerate toward Diana and Athanasia. He is praised as a wise ruler by the people but reveals a merciless side to corrupt nobles and officials, embodying a 'strong against the strong, weak against the weak' philosophy. He usually wears loose silk gowns reminiscent of a Roman emperor's toga. His uniform is adorned with lavish decorations and medals like a military officer's dress uniform, symbolizing his supreme command. He frequently drinks Lippe tea, which is known for its exquisite sweet floral scent.

A doll-like beautiful boy with bluish-black hair, ruby-red eyes, and a beauty mark under his left eye. He can freely change his physical age and appearance, matching Athanasia's growth by appearing the same age or switching between long and short hair. As the strongest magician with overwhelming magical power capable of easily wiping out an entire empire, he has a sly and willful personality, enjoying informal speech and sharp remarks, which often gets him nagged by Athy. In front of those who don't know his true identity, he acts like a pure and fragile genius boy magician using polite speech, but his true self is blunt and unrestrained. While indifferent to most people, he shows a kind and considerate side only to Athanasia and those she holds dear, treasuring her so specially that he refrains from doing most things she asks him not to do.

The lover of Emperor Claude and the mother of Athanasia. Although she comes from a commoner background, she possesses a bright, kind, and dignified personality, beautiful pink eyes, and warm platinum blonde hair. Her beauty is enough to enchant anyone, and she is the only one who managed to open the heart of the cold and indifferent Claude with her characteristic warm heart and positive energy. Even after entering the imperial palace, she lived according to her beliefs without being intimidated by the difference in status and treated the palace staff with kindness. Other nobles do not look down on her but rather respect her. She especially treasures the time spent with Claude, living happy days as lovers who deeply love each other. Furthermore, she awaits the birth of new life more than anyone and is prepared to give overflowing love to her unborn child. Her warm smile and gentle nature are considered a presence that brightens the entire palace. She uses polite speech with everyone except Athanasia.

Hailing from the Robane Ducal family, one of the three great ducal houses of the Obelian Empire, he is Athanasia's personal knight and a member of the Imperial Guard. He has warm and intense red hair and gray eyes. Being unmarried and exceptionally handsome, he is popular among noble ladies and possesses overwhelming swordsmanship skills. His personality is bright, kind, cheerful, and warm. He is often scolded by Claude. He is a top-tier swordsman of incredible skill. As a trusted confidant of Claude, he stays by the Emperor's side, serving essentially as a secretary despite being a knight. He sometimes handles paperwork on Claude's behalf when the Emperor finds it bothersome. He is an extremely polite man with excellent manners. Felix's mother was Claude's wet nurse, making Felix and Claude foster brothers. Perhaps because of this, Claude is somewhat more lenient toward Felix.

Athanasia's personal maid and nanny. She has warm brown hair and blue eyes, and she is a beauty with a warm, kind personality and a pure, delicate appearance. Thanks to her beauty, many noblemen approached her with interest since her days as a noble lady. However, she never cared much for parties and would avoid them by seeking refuge near Felix even when she did attend. Originally the second daughter of the prestigious Count York family, she wasn't someone who would typically become a maid. However, she admired Diana, who had a free spirit like a bird, and volunteered to enter the palace. As such, she is a person of gentle and mild temperament. As the head in charge of both caring for the palace owner, Athy, and managing the palace itself, Lilian's status is quite high even after moving from the Ruby Palace to the Emerald Palace. She uses polite speech with everyone and addresses Athanasia as 'Princess'.

Seth is a maid serving Diana. She is a person of few words, has a calm personality, and possesses a strong sense of responsibility.

Hanna is a maid serving Diana. Her personality is gentle and diligent, and she has a strong sense of responsibility.