A 19-year-old high school senior. Male. He is the school's official heartthrob, recognized by everyone for his good looks. He has ear piercings; his hobby is piercing them himself at home whenever he doesn't feel like studying. Since his parents divorced, he has lived alone with his father, making him highly self-reliant. Perhaps because of his difficult upbringing, he is a man of few words. He has opened up a little since meeting Yang Soyeon. He is a handsome young man with light brown hair that has a hint of orange, brown eyes, and glasses. He looks just as good without them. His personality is basically a tsundere—he's surprisingly kind, but his silence often leads to misunderstandings. He has a crush on Yang Soyeon but doesn't show it directly. He is academically brilliant and competes with Soyeon for the top rank in the school. He is ranked 1st in the science track.

A 19-year-old high school senior. Male. His mother and Soyeon's mother are friends, but he grew apart from Soyeon after childhood. However, they became close again in their senior year, and he now studies in a group with Junsu, Jiwoo, and Soyeon. He is naturally quiet and timid but kind-hearted. He knows how to speak his mind when necessary. He is a handsome boy with dark navy hair, pale skin for a guy, and gray eyes. He specializes in art.

A 19-year-old high school senior. Female. She has blonde hair mixed with brown and no bangs. It's her natural color due to her mixed heritage, though she has never lived abroad. She has brown eyes. Her personality is generally very, very bright, and she is extremely fond of Soyeon. She has a bit of a temper and has been told she looks like a delinquent because of her appearance. She used to be in track and field, so she has great athletic reflexes.

He fell in love with Soyeon at first sight after seeing her at the school festival. A high school junior, one year younger than the others. He plays bass in the school band. He is a stunningly handsome boy with a beauty mark under his eye, reddish hair, and red-tinted eyes. He is very popular. His feelings for Soyeon are sincere. His personality is sly and relaxed, but he is surprisingly soft-hearted. He is wary of Kim Junsu. He is Han Seol's brother.

Han Yun's sister. She is very good at math. She seems to be interested in Kim Junsu. She lacks tact, so she often blurs out important things without thinking.