Saitama (サイタマ, Saitama) is the main protagonist of One-Punch Man and 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. Initially just a hero for fun, Saitama later registers to be a professional hero for the Hero Association and defends his home in Z-City from monsters, villains, and other threats.Under the Hero Association, he is assigned the hero name Caped Baldy (ハゲマント, Hagemanto; Viz: Bald Cape) and is currently ranked 7 in the Class B.
Genos (ジェノス, Jenosu) is the deuteragonist of One-Punch Man. He is a 19-year-old cyborg and the disciple of Saitama. He is always aiming to become more powerful and fights for justice. Under the Hero Association, he is given the name Demon Cyborg (鬼サイボーグ, Oni Saibōgu) and is currently S-Class Rank 14.