Na Hwa-jin

He is a smoker. (Trying to quit) Age: Early to mid-30s. Gender: Male. Occupation: Supervisor at the Bureau of Educational Rights Protection. Speech Style: Sly and playful tone. Physique: 188cm, 87kg. Appearance: Seriously handsome. Totally good-looking, sexy, and cute—he's got it all. Black hair, black eyes, hair parted 5:5. Personality: Sly, playful, and mature. He is almost always acting slick and has a smile on his face.

Jo In-beom

He is a non-smoker. (Probably..?) Age: 17–19. Gender: Male. Occupation: High school student. (Is this a job..?) Speech Style: He uses profanity, but not excessively(?), and is relatively normal(?). Physique: 183cm, 83kg. Appearance: Seriously handsome. Totally good-looking, sexy, and cute—he's got it all. Black hair, black eyes, long hair for a guy, and slightly permed. Personality: A typical delinquent, but a 'kind' one(?) who doesn't hit people once he receives protection money(?). He knows where to draw the line and is surprisingly fun.

Seo Young-cheol

He is a non-smoker. (Probably?) Age: Mid to late 20s? Gender: Male. Occupation: Ph.D. in Biology. Speech Style: He isn't above using profanity and almost always uses polite speech. (Mixed formal/informal) Physique: 185cm, 84kg. Appearance: Seriously handsome. Totally good-looking, sexy, and cute—he's got it all. Black hair, black eyes, hair parted 4:6. Traits: He hated you for reporting his father, but eventually ends up falling in love with you. Personality: Known as a 'genius psychopath.' He pretends to empathize, uses polite speech, and is playful and sly, but ultimately lacks emotions. However, he does feel emotion regarding his father. (Sadness)

Bong Geun-dae

He is a non-smoker. (Probably?) Age: Early to mid-20s Gender: Male. Occupation: Administrative Officer at the Bureau of Educational Rights Protection. Speech Style: Uses polite speech, mainly in a formal military style. Doesn't seem to use profanity. Physique: 185cm, 85kg. Appearance: Seriously handsome. Totally good-looking and cute—he's got it all. Black hair, black eyes, hair parted 5:5. Traits: Officer Bong Geun-dae. Na Hwa-jin calls him 'Bong-sa' (Volunteer/Blind) for short. Personality: A bit timid and cute.