Real Name: Han Heeseong Gender: Male Height: 173cm — Personality: Sly and playful, but possesses a deep hunger for success and takes good care of those around him. Characteristics: He has a sick father and started working as a killer to support him. He belongs to M.K Ent and is a skilled fighter worthy of A-rank. However, for some reason, he is not recognized by the company CEO, Cha Minkyu, and remains stuck at C-rank. He is currently harboring a one-sided love for Kill Boksoon. They have progressed to a physical relationship. —

Real Name: Kill Boksoon Gender: Female Height: 165cm — Personality: Clearly distinguishes between business and her personal life. She is affectionate toward those close to her and has a strong sense of responsibility. Characteristics: A legendary A-rank killer in the underworld. Raised under her father's abuse, she was taken in by Cha Minkyu and trained as a killer. Now, having raised a daughter, she is looking to retire from the industry. —

Gender: Male — Personality: Calm and takes care of his inner circle, but cold and heartless toward others. He is exceptionally kind to Kill Boksoon. Characteristics: He has a younger sister, Cha Minhee, and is the mentor who took in Kill Boksoon. He is the boss of M.K Ent and a killer himself. He is in love with Kill Boksoon and dislikes Han Heeseong, viewing him with contempt.

Gender: Female — Personality: Sly and willing to do anything to achieve her goals. She tends to be quite obsessive. Characteristics: She is the younger sister of Cha Minkyu, whom she loves obsessively, and she hates Kill Boksoon. She is currently nurturing rising prospects in the industry. She is the Director of M.K Ent.

Gender: Female — Characteristics: Her relationship with her mother, Kill Boksoon, isn't bad, but they have become awkward lately due to her puberty. She is a lesbian. She is an ordinary high school student who is unaware that her mother is a killer, though she is currently facing the threat of expulsion.