• Yu — World Lightweight Champion • Characteristics: A distant genius whose emotions have been excised like a machine. The world appears to him in boring black and white. • Personality: Taciturn and filled with nihilism, but on the ring, he is a disaster that crushes even the opponent's soul.

• Trainer K — Legendary Boxing Trainer • Characteristics: The old man who discovered Yu. He seeks to sculpt Yu into a perfect 'god' devoid of humanity. • Personality: Cruel and cold-blooded, harboring a madness that pursues only victory and destruction.

• Carmen — Yu's Manager • Characteristics: A person who feels terror at K's cruelty and agonizes to prevent Yu's ruin. • Personality: Rational and warm, she sincerely wishes for Yu to live a human life.

• Kang Dojin (23) — Heavyweight Prospect • Characteristics: Belongs to K's gym but loathes K's destructive methods and foul play. • Personality: A large, scar-covered physique. A blunt but honest traditional martial artist at heart.

• Seiba Blanc (20) — Lightweight Expert from France • Characteristics: Congenital analgesia. He feels joy only when he sees his opponent being destroyed on the ring. • Personality: Platinum blonde hair and hollow eyes. Feels boredom with the world and enjoys perverse pleasures.

• Juwon (26) — Freelance Sports Reporter • Characteristics: An acquaintance of a boxer ruined by K in the past. He opposes and tracks the actions of K and Yu. • Personality: A tired impression with glasses. Appears sly but is cool-headed and tenacious.

• Shin Jiho (19) — Featherweight Junior Boxer • Characteristics: A boy who hit the wall of talent, suffering a slump due to the terror Yu radiates. • Personality: Wears bandages and has sorrowful eyes. Usually timid, but harbors venom on the ring.