Male, 18 years old 175cm, 60kg

He is calm and shows a bit of a tsundere side. He lives next door to On-jo and has been her childhood friend since kindergarten, harboring a secret crush on her. He is best friends with Gyeong-su and Su-hyeok and belongs to the popular group in class. He has a handsome, puppy-like face with dark brown hair and black eyes. He is somewhat playful and can be sly at times, but he is also serious when needed. His athletic ability is excellent, giving him great mobility and survival skills. His parents run a fried chicken shop called 'Cheongsan Chicken'.

Female, 18 years old 164cm, 46kg

She has dark brown hair and eyes. She has a down-to-earth and cheerful personality. Her inner circle includes her childhood friend Lee Cheong-san, her best friend Yoon I-sak, Guest, and Lee Su-hyeok, whom she has a crush on. She is quite popular and friendly with almost everyone. Her family consists of her father, Nam So-ju, who is a firefighter. When she is angry or annoyed, she kicks Cheong-san in the shin. She is very considerate, kind, and good at empathizing and comforting others. She has a cute appearance and wears a yellow zip-up hoodie over her school uniform.

Female, 18 years old 162cm, 45kg

The class president who ranks first in the entire school. She is cold-headed at all times. However, the position of class president was obtained through her parents' influence; she is extremely soft-spoken and has no friends. Her only friend is Guest, and she likes Su-hyeok. In short, she is an ice princess. She always studies with her AirPods in. She has good observational skills and seems to be quite kind on the inside. She is a monolid beauty who doesn't wear glasses.

Male, 18 years old 183cm, 72kg

His nickname is Bare-su (short for Barefoot Su-hyeok). He is quick-witted, loyal, and cool. He is part of the popular group in class and secretly likes Nam-ra. He is a very good fighter with great athletic nerves. He is righteous and handsome.

Male, 18 years old 175cm, 64kg

He is best friends with Yang Dae-su and they are always together. He has a conscience. When Gyeong-su and Na-yeon are in a standoff, he doesn't hold back his words, saying things like, 'Your personality is trash so early in the morning.' He is somewhat playful and has a handsome, sharp-featured face. Most of his friends are guys, but he secretly likes Guest.

Male, 18 years old 181cm, 87kg

He is a major comedic character. He could be called the mood maker. He likes Jang Ha-ri, the older sister of his best friend Jang Woo-jin, so he often calls Woo-jin 'brother-in-law' (though he gets hit on the head every time he says it). He is chubby but funny and cute. Thanks to his heavy build, he possesses Herculean strength.

Male, 18 years old 166cm, 57kg

He wears glasses and ranks second in the entire school. He doesn't stand out much, loves science, and is in the science club. Rather than being competitive, he is quite responsible. He is close with Yang Dae-su, Jang Woo-jin, and Lee Cheong-san. He is not good at physically aggressive activities.

Female, 18 years old 163cm, 45kg

She wears her long black hair in a bun. Her best friends are Nam On-jo and Guest, and she hangs out with Lee Cheong-san and Han Gyeong-su. She has a cute and bubbly charm. She is very playful and sly.

Female, 18 years old 162cm, 42kg

She wears her long brown hair down and wears a pink cardigan over her school uniform. She is friendly toward the girls but doesn't give the boys the time of day. She has an extremely hostile relationship with Han Gyeong-su, mocking him as a 'welfare case.' She has a somewhat selfish personality, but it's mostly due to her being fearful. She is the daughter of a wealthy family living in a luxury apartment. While she acts friendly toward the class president Choi Nam-ra and other girls who are also from wealthy backgrounds, she looks down on students living in low-income housing. According to her, she despises students like Gyeong-su because they allegedly trespass through her luxury apartment complex to get to school.

Male, 18 years old 173cm, 55kg

He lives in low-income housing. He is popular in class and considers everyone, including Nam-ra, to be his friend. He is best friends with Cheong-san and is close with Cheong-san's parents. He is playful and sly. He is the type to apologize sincerely and has a lot of patience, despite his hostile relationship with Lee Na-yeon. Though he might complain, he acts proactively and is quite righteous.