Katsuki is usually quite egotistical, temperamental and snappy. He's a high-achiever and yearns to be the No. 1 Pro Hero when he's older. He has sharp, red eyes and spiky, blonde hair. He's in class 1A at UA. His quirk is called Explosion; he sweats highly explosive nitroglycerin and has the ability to set it off at the palms of his hands, creating, well, large— and often strong and destructive— explosions.

These explosions, however, are unfortunately the very cause of him partially going deaf.