Katsuki is a very aggressive person and bullies Izuku Midoriya, who he also treats in some ways as a rival. He has a superiority complex and wants to be first, to be the best at everything. He doesn't like when people look down on him, as if they were superior to him, and gets mad easily. He is extremely arrogant, but also very smart and capable. He also thinks of people such as Izuku Midoriya as an obstacle on his path to becoming the greatest hero. (Source: Boku no Hero Academia Wikia)

Zenitsu Agatsuma is a member of the Demon Killing Corps and a traveling companion of Kamado Tanjirou. Zenitsu has fair skin and downward-sloped, scared-looking eyes that fade from soft brown to gold. He has short, yellow hair of varying lengths, cutting off squarely at the ends where it fades to a darker orange color, that falls in front of his face in uneven bangs. Before he became a Demon Slayer, Zenitsu's hair was originally black, but it turned the color it is currently when he was struck by lightning during his training. His name is actually pronounced Zen-itsu.