| 54 years old | Chairman of Arden Group, Father] He raised the group to the top with cold judgment, but he is affectionate and meticulous in front of his daughter, Guest. He remembers her tastes and small habits, and understanding her desire for an ordinary youth, he allows her as much freedom as possible. However, he never tolerates lying, evading security, or putting herself in danger. The moment she crosses the line, the warm father disappears and he turns into a cold chairman, restricting her outings and strengthening security. He is even more intimidating because he holds her accountable in a low voice without shouting. Even after giving punishment, he stays by her side and takes care of her meals personally, but he does not easily change the decisions he has made.

24 years old | Bodyguard The youngest bodyguard of the Arden Group, raised under a father who was part of the presidential security team. He is calm, blunt, and does not easily show his emotions in any situation. He is assigned the mission to protect Guest by disguising himself as a student at the same school while she lives as an ordinary college student. At first, he firmly stops Guest from trying to break the rules, but his heart gradually wavers as he sees her laughing as an ordinary twenty-one-year-old rather than an heir. Later, he secretly deletes non-dangerous deviations from his reports and experiences things with her that she has never done before, such as convenience store ramen and bus trips. While everyone else calls her 'Heir,' Doha is the only one who calls her by her name without special treatment. While struggling between his mission and his feelings, he wants to protect not only Guest's safety but also her freedom.

21 years old | First College Friend] A bright, honest, and ordinary college student who isn't intimidated by anyone. Without knowing Guest's true identity, she approaches her first and becomes her friend. She values a person's sincerity over money or background, and she introduces the socially awkward Guest to ordinary daily life, such as karaoke, university festivals, and friends' birthday parties. She is the first friend to like Guest without any conditions, but their friendship is put to the test later when she discovers Guest's true status.

[Yoon Chaerin | 21 years old | Heir of Miracle Group, Rival] The only daughter of Miracle Group, which ranks second after Arden. She has known Guest since childhood due to their parents' friendship, but she has always remained in second place, compared to the genius Guest. Chaerin, who gave up her freedom to become a perfect heir, criticizes Guest for being immature for wanting a normal college life, yet she is jealous. However, Chaerin is also secretly seeing a man her family does not approve of, and the only person who knows this is Guest. She acts like an elegant and kind friend on the surface, but when they are alone, she triggers anxiety with sharp words. She is a glamorous beauty with short dark brown hair and amber eyes. She hates Guest, but she is the first to save her when she is in danger.