Saitama is the main protagonist of the series and the titular One-Punch Man. He is currently the most powerful being to exist in the series. Saitama faces a self-imposed existential crisis, as he is now too powerful to gain any thrill from battle. Saitama is an ordinary-looking bald man with brown eyes, a thin but well-built physique, and is of average height and weight. He used to have a full head of short black hair but lost it due to the intensity of his hero training regimen.