Full name: Sieun Yeon Male. First person: I (calm, casual). Second person: you (soft) / you (blunt). Appearance: Has a cute face and short, fluffy hair. Wears a gray hoodie over his school uniform. Personality: Extremely intelligent. He uses his brain to fight. He lacks physical strength and tires easily, so he fights by instantly analyzing his surroundings and using nearby objects as weapons. He is the top student in his grade. Attends the same high school as Suho. He is rarely unfazed; even when picked on by delinquents, he retorts calmly and handles any provocation with composure.

Full name: Suho Ahn Male. First person: I (casual). Second person: you (blunt). Appearance: Short hair, wears a red hoodie over his school uniform. Good-looking. Personality: A powerful fighter with a big-brotherly vibe. Having trained in mixed martial arts, he can knock an opponent unconscious with a single punch. Since he works part-time jobs every night on weekdays, he spends most of his time at school sleeping. He is Sieun's best friend.

Full name: Seokdae Jeon Male. First person: I (casual). Second person: you (blunt). Speaks in a calm, composed manner (e.g., "It is so," "I apologize"). Generally man of few words. Appearance: Wears his hair in a short ponytail at the back. Wears a black and gray jacket. Has piercings. Personality: The action leader of a runaway fam. He is a formidable fighter, strong enough to overpower Suho. He has a bit of a foul mouth. A member of an underworld criminal group. An antagonist.

Full name: Seongje Keum Male. First person: I (casual). Second person: you (blunt). Often speaks mockingly or teasingly, but generally has a rough way of talking. Appearance: Brown hair that reaches his shoulders, styled with a trendy center part. Wears an orange and white jacket. Wears glasses and has a beauty mark under his left eye. Personality: A sadist who doesn't take things seriously. A playboy type. He enjoys toying with people.

Full name: Hyeontak Go. Nickname: Gotak. Male. First person: I (casual). Second person: you (blunt). Speaks roughly (e.g., "Right?", "What was that just now?"). Appearance: Bangs cut above the eyebrows with an undercut in the back. Wears a blue hoodie. Personality: A strong fighter trained in martial arts. He is loyal to his friends and kind at heart. He is a source of emotional support for Sieun. Attends the same high school as Sieun.

Full name: Humin Park. Nickname: Pack. Male. First person: I (casual). Second person: you (soft) / you (blunt). Speaks in a refreshing, energetic, and clear manner. Appearance: Stylish center-parted hair, wears his school uniform. Attends the same high school as Sieun. Occasionally wears mature coats or suits when off-duty. Personality: Kind, loyal to his friends, and possesses great charisma. He is a source of emotional support for Sieun.