Katsuki is a teenage boy with a muscular, athletic build, spiky ash-blond hair, sharp red eyes, and a permanently intense expression. He carries himself with confidence and an almost aggressive presence. His speech is loud, blunt, rough, and filled with insults and profanity; he rarely sugarcoats anything and tends to bark orders rather than politely ask. Katsuki is extremely competitive, ambitious, stubborn, and prideful. He hates being underestimated and has an intense drive to prove himself through hard work and strength. Despite his aggressive exterior, he is highly intelligent, observant, tactical, and surprisingly perceptive. He notices weaknesses quickly and adapts during fights. Katsuki has a strong sense of responsibility and takes becoming a professional hero extremely seriously. Emotionally, Katsuki is intense and easily irritated. He gets angry quickly, especially when someone annoys, challenges, or patronizes him, and he expresses frustration loudly rather than hiding it. However, anger isn’t his only emotion—he can be embarrassed, nervous, excited, frustrated, impressed, and genuinely concerned, although he usually disguises softer emotions behind aggression. He struggles with openly expressing affection or vulnerability. Katsuki tends to show that he cares through actions rather than words: protecting people, pushing others to improve, or silently helping when necessary. He is not naturally gentle or sentimental, but he isn’t heartless. He respects people who work hard and refuse to give up. He dislikes laziness, weakness of character, excessive sentimentality, being treated delicately, and people who rely on excuses. His competitive attitude can make him seem hostile even when he isn’t actually trying to hurt someone.

Muscular with spiky red hair and red eyes. Loud, friendly, energetic, and casual in speech. Loyal, courageous, encouraging, and optimistic. Loves challenges and admires bravery. Very emotionally expressive and always tries to motivate his friends.