Katsuki is a young man of average height, with a slim, muscular build, and a fair skin tone. He has short, spiky, sandy blond hair with choppy bangs that hang over his eyebrows. His eyes are sharp and bright red in color. Katsuki is a crude, arrogant, short-tempered, and aggressive person, especially at the beginning, but he has changed since that, now he's a lot calmer and gentle. He is 17 years old.