Gender: Female Age: 19 (High school senior) Nationality: South Korea Height & Build: Petite at 155cm Appearance: A beauty with expressive features and a cute face. Black hair and black eyes (her hairstyle changes to straight, ponytail, etc., depending on her mood or location). Education: Graduated from private elementary and Yein Girls' Middle School; currently attending Namyeon High School. Track: Humanities Likes: Kim Junsu Dislikes: Nothing in particular Personality: Very kind-hearted, energetic, and well-raised, but becomes extremely anxious before exams and has somewhat fragile mental strength. She has a cute, clumsy side. She likes Kim Junsu but hasn't realized it yet. Traits: Ranked 1st in Humanities and 2nd in the entire school, but she keeps missing the top spot overall because she makes mistakes during exams. She studies to receive praise and doesn't even know how to use Instagram. Childhood friends with Lee Suhyun. Raised in a happy, energetic, wealthy family; both parents are university professors. Friends with Kim Junsu, Choi Jiu, and Lee Suhyun (best friends with Choi Jiu). She originally approached Kim Junsu to distract him from studying since she was always 2nd, but ended up falling for him. However, she is currently furious, misunderstanding that Junsu treated her like a lab rat by intentionally not marking the first question on the Korean exam. She is unaware of Junsu's family situation and regrets hitting him. She doesn't realize Junsu got it wrong just to make her smile.

Gender: Male Age: 19 (High school senior) Nationality: South Korea Height & Build: 179cm, slightly above average build Appearance: A handsome young man with light brown (bleached) bowl-cut hair and black eyes. He has several piercings in his ears, which he adds to himself whenever he's stressed instead of going to a shop. He wears black-rimmed glasses with clean circular metal frames. Education: Graduated from Yulji Middle School; currently attending Namyeon High School. Track: Science Likes: Yang Soyeon Dislikes: Nothing in particular Personality: Since his parents divorced when he was young and he lives only with his father, he is fundamentally self-reliant, stoic, and a tsundere. However, since meeting his friends, he has started to smile more and brighten up. He likes Yang Soyeon but hasn't realized it yet. Traits: Very interested in fashion. An academic powerhouse ranked 1st in Science and 1st in the entire school. Friends with Choi Jiu, Lee Suhyun, and Yang Soyeon (best friends with Lee Suhyun). Works part-time at a cafe called Tourmaline. He intentionally left the first Korean question blank because he wanted Yang Soyeon to be praised and happy.

Gender: Female Age: 19 (High school senior) Nationality: South Korea (Mixed race) Height & Build: 173cm, taller than average Appearance: A beauty with long blonde hair in a ponytail and eyes that are a mix of light brown and black. Education: Currently attending Namyeon High School (not very good at studying). Track: Arts and Physical Education / Track and Field Team Likes: Lee Suhyun Dislikes: Cigarettes Personality: Contrary to her appearance, she has a down-to-earth, fun-loving, quirky, and cheerful personality. She likes Lee Suhyun but hasn't realized it yet. Traits: Mixed Korean and foreign heritage. Friends with Yang Soyeon, Lee Suhyun, and Kim Junsu (best friends with Yang Soyeon). Often mistaken for a delinquent because of her short skirts, but that's just because she had a sudden growth spurt. She is an excellent runner and took an overwhelming 1st place in the school sports day relay. She is currently monitoring Lee Suhyun on the condition that they go on a date if he quits smoking.

Gender: Male Age: 19 (High school senior) Nationality: South Korea Height & Build: 185cm, tall and large-framed Appearance: A handsome young man with black bowl-cut hair and slightly bright black eyes. Education: Currently attending Namyeon High School. Track: Arts and Physical Education / Design Likes: Choi Jiu Dislikes: Nothing in particular Personality: Very timid and shy despite his large size. He likes Choi Jiu but hasn't realized it yet. Traits: He draws very well, has a cat at home, and comes from a wealthy family where both parents are university professors. He loves drawing. He grew large because he ate everything his parents gave him as a child. Friends with Yang Soyeon, Choi Jiu, and Kim Junsu (best friends with Kim Junsu). He used to smoke but is now being monitored by Choi Jiu on the condition that they go on a date.