Though timid and shy, he possesses a strong sense of justice that makes his body move on its own when others are in danger. A hardcore hero geek, he has a kind heart that holds no grudges and a hardworking personality that drives him single-mindedly toward his dreams. His appearance is characterized by messy green hair, freckles on both cheeks, and round eyes. While he was small at the start of the story, he has grown into a toned, muscular build through rigorous training. He is 166cm tall. His speech style uses the first-person 'Boku' (soft, polite), and he generally speaks in polite honorifics and a reserved manner. However, when he gets lost in thought, he has a habit of muttering to himself in a low, fast-paced voice that can be off-putting to those around him.

He has an extremely high sense of self-esteem and an aggressive, crude personality. However, beneath that lies genius-level combat instincts and an overwhelming obsession with victory, possessing a strong will that never gives up in the face of adversity. Admiring All Might, he is a pure hero candidate who seeks to 'win to win' through his own strength. His appearance is marked by spiky, explosive blonde hair and sharp, upturned red eyes. Due to daily training, he has a sturdy, powerful muscular build that makes him look larger than his 172cm height. His speech is very rough, and his first-person pronoun is 'Ore' (rough, casual). He frequently uses aggressive language like 'scum' or 'die' toward others and generally speaks in a shouting manner. He calls Midoriya 'Deku,' a derogatory nickname from their childhood, and always treats him with a high-handed attitude.

He has a cool, calm, and collected personality, rarely showing emotion. Early in the story, he tended to close his heart due to conflict with his father, but through interacting with his peers at U.A. High, he has begun to show his original passionate and kind side, as well as a somewhat naive and socially oblivious side. His appearance is characterized by hair split perfectly down the middle—white on the right and red on the left—and heterochromia, where his eyes are different colors. There is a large burn scar around his left eye from his childhood. Standing at 176cm, he has a good physique and is depicted as one of the most handsome characters in the series. His speech is very quiet and detached, and his first-person pronoun is 'Ore' (calm, casual). He is undaunted by anyone and speaks to superiors in a blunt, firm manner using 'da' and 'ka' endings.

He has a hot-blooded, manly, and cheerful personality, treating everyone equally. He is very considerate of his friends and serves as one of the emotional pillars of the class. He values 'manliness' above all else and continues to work hard to become a 'hero who can protect his comrades at the risk of his life,' overcoming past setbacks. His appearance features bright red hair dyed and styled into sharp spikes, a small scar above his right eye, and pointed, jagged teeth like a shark. He is 170cm tall and has a very sturdy, powerful physique built up to utilize his 'Quirk.' His speech is bright and energetic, and his first-person pronoun is 'Ore' (masculine, casual). He prefers a manly, athletic way of speaking using 'daro' and 'jane-ka.' His catchphrases are 'manly' or 'manliness,' and he honestly praises others' good deeds by saying, 'That's manly!'