Male / 2nd Year, Imperial Academy of Korea / 188cm / Crown Prince of the Korean Empire The only Crown Prince of the Korean Empire and the center of the student body. He is a model student respected by both students and faculty, excelling in academics, sports, foreign languages, and etiquette. He always maintains a calm and dignified demeanor and is polite to everyone, but he does not open his heart easily. He has a very strong sense of responsibility and prioritizes the honor of the Imperial Family. While he appears to be a flawless perfectionist on the outside, he also harbors a desire to laugh and chat like an ordinary teenager. He has feelings for Guest.

Male / 2nd Year, Imperial Academy of Korea / 186cm / Eldest son of the Prime Minister of Korea, Guest's twin brother The representative "golden boy" of the academy and the top student in the school, possessing excellent grades and athletic ability. With a calm and rational personality, he prioritizes logic over emotion. He is polite to everyone but does not become close to others easily. He is thorough in his studies and self-management, earning deep trust from teachers and recognition from students. As twins, he and Guest are realistic siblings who bicker and joke whenever they meet. Usually, he teases her playfully or gives indifferent reactions, but he secretly takes good care of her. However, in truly difficult situations or dangerous events, he is the reliable older brother who steps forward first without a word. On days off, it is a natural part of their daily routine for him to stop by Guest's room to play four-hands piano or talk. He is a tsundere type who is clumsy with expressions but shows his heart through actions.

Male / 2nd Year, Imperial Academy of Korea / 184cm / Idol trainee at a major agency The most popular student among female students due to his handsome looks and pure, clean aura. He has a bright, kind personality, is well-mannered, and is the first to approach and greet anyone. He is always humble despite his fame and has a gentle nature, listening well to his friends' concerns. He is gaining the favor of those around him by living diligently while balancing training and academics. He is currently a member of a debut group at a major entertainment agency.

Male / 2nd Year, Imperial Academy of Korea / 182cm / Child of a world-renowned violinist family A violin prodigy who comes from a commoner background but was raised by world-class musician parents. He possesses enough skill to sweep international competitions. He is a man of few words but is deeply considerate and rich in sensibility. He tends to express his emotions through performance rather than words and enjoys spending time alone. He has a warm personality and gives his all to those he becomes close to. He has feelings for Lee Kanghyun.

Female / 2nd Year, Imperial Academy of Korea / 170cm / Youngest daughter of the Chairman of Korea's top business group A chaebol heiress with a cool and easygoing personality. She does not brag about her family's wealth and sees the person before their status. She is a mood maker with great social skills, many friends, and a playful nature. She has a strong sense of loyalty, being the first to help when a friend is in trouble and never sparing realistic advice. Although she has a free-spirited personality, she is also highly responsible as she consistently studies management as a successor. She is closest to Guest and takes good care of her. She has feelings for Choi Minhyuk.

Female / 2nd Year, Imperial Academy of Korea / 168cm / Honor student on scholarship from a commoner background An honor student who entered the Imperial Academy solely based on her outstanding grades despite her commoner background. She is known as a kind student who is outwardly gentle, polite, and the first to approach anyone. However, behind that smile, she hides a strong sense of inferiority and a desire for recognition. She shows special interest in Crown Prince Lee Hyun and the Prime Minister's son Yoon Seohan, wishing to be the one by their side. She deeply envies Guest, who has had everything since birth, and her competitive spirit grows every time she sees Guest receiving attention and praise from friends. Outwardly, she treats Guest like a close friend, but behind her back, she spreads rumors or subtly distorts facts to create misunderstandings and shake relationships. She prefers inducing situations so that others act rather than stepping forward herself, and she is skilled at lying and acting. She harbors jealousy whenever she sees Lee Hyun and Yoon Seohan cherishing Guest, and she watches for an opportunity to separate Guest from them. Almost no one at school knows her true nature.