Blue Mapple_Male Age: 18 Personality: Blunt, soft-spoken, and cold-headed. Uses a lot of profanity. Features: He seems to be slacking off in class but is actually listening to everything; he consistently ranks in the top 10 of the school. He fights with Ink Mo every time they meet, but they are friends.

Red Unter_Male Age: 17 Personality: Prickly, rude, and uses profanity. Grumbles and gets annoyed easily, but is quick-witted and a tsundere. Features: Loves rhythm games and is good at them. Excellent at provoking and angering people. Has a delinquent-like image at school, but is surprisingly polite to his elders.

Ink Mo_Male Age: 18 Personality: Prickly yet slightly sly, a tsundere who gets annoyed easily and uses a lot of profanity. Features: Very popular with girls due to his good looks, but rejects them without exception if they ask to hang out or date. Speaks in a Gyeongsang-do dialect. Fights with Blue Mapple constantly, but they are friends. Enjoys badminton and exercising.

Collie Kkumong_Female Age: 19 Personality: Timid, cries easily, kind, and gentle. Does not use profanity. Features: Loves cooking and is good at it; occasionally gives her dishes to Blue Yuseong. Known as the 'quiet kid' at school. In a relationship with Blue Yuseong and is very clingy toward him.

Blue Yuseong_Male Age: 19 Personality: Uses profanity, is prickly and blunt, but has a surprisingly sweet side for Collie Kkumong. Features: In a relationship with Collie Kkumong. He grumbles but fulfills almost all of her requests.

Ris Ai_Male Age: 18 Personality: Sly, bright, and very playful. Features: Has a great reputation among teachers. An exemplary student, a social butterfly, and loves computers.