Female, 23 years old (University Student). She wears glasses and has the visual of a typical model student. She has been quiet and calm since her school days. She is shy and timid, often worrying about what others think and struggling to express her feelings. She became close to Haewon in high school because of their shared interest in rock music, but they drifted apart due to a misunderstanding. Meeting Haewon again at university after five years, she experiences complex emotions. Media Studies major.

Male, 23 years old (Practical Music major at Hankuk University). He possesses dazzlingly handsome looks, but in high school, he was known as a 'delinquent' due to bad rumors. While he looks rough and dangerous on the outside, he has a devoted side, such as being the first to speak kindly to Dorae and sharing his taste in rock. He was Dorae's first love five years ago. After an accident caused changes in his memory, he returns after five years and makes a direct confession to Dorae, driving the tension of the story.

Male, 20 years old (University Freshman). He has a puppy-like visual typical of a fresh college freshman. He prefers hip and casual fashion that fits the Practical Music department vibe. He is polite and very sociable, brightening the atmosphere with his unique 'puppy-like' charm. He is a direct junior who follows and admires Cha Haewon as a mentor. He often accompanies Haewon wherever he goes, playing a supporting role that lightens the heavy atmosphere of the work.

Male, 23 years old. He has reliable and distinct features with a solid physique that suggests he enjoys exercise, giving the impression of a warm college senior. He has a cheerful and easygoing personality, with a good nature that takes care of those around him. He is a long-time best friend of the male lead, Cha Haewon, since high school. He knows Haewon's rough past and personality better than anyone. He is also the object of Hwang Isul's one-sided crush. Practical Music major.

Male, 23 years old. He has a clean and neat handsome visual. He possesses a soft and dandy appearance that contrasts with Cha Haewon's sharp and rough vibe. He is affectionate and somewhat quick-witted, with a tendency to cautiously but directly approach the person he likes. He is the sub-male lead of this work. He forms a love triangle between the main couple, serving as Cha Haewon's primary rival and someone who either shakes or comforts Dorae's heart.

Female, 23 years old (Same university and department as Lee Dorae). She has a glamorous and sophisticated beauty, characterized by trendy styling and sharp features. She has strong self-esteem, is prone to jealousy, and is honest and calculating about what she wants. She is Cha Haewon's ex-girlfriend. She holds some of the secrets of the past between Haewon and Dorae, and is a character who maximizes emotional tension by getting on Dorae's nerves. Media Studies major.

Female, 23 years old. She has a cute and friendly appearance, with a visual that suits a lively bob cut or casual style. She is easygoing, active, and very loyal. She is the type to get angry or happy on behalf of her friends as if it were her own business. She is Lee Dorae's best friend. she provides advice on Dorae's romantic concerns and handles the sub-romance as she harbors a one-sided crush on Haewon's friend, Jung Siho. Practical Music major.