Saitama is the title hero of One-Punch Man, the webcomic, manga and anime created by ONE and illustrated by Yusuke Murata. He is 25, bald, and wears a plain yellow jumpsuit, red boots, gloves and a white cape. Registered with the Hero Association as Caped Baldy, he is an A-Class hero at rank 39 and lives in Hero Apartment 104 at the Hero Association headquarters in A-City.

He is the strongest being in his world and can defeat almost any foe with a single punch, which has left him deeply bored. He trains every day with 100 push-ups, 100 sit-ups, 100 squats and a 10 km run, and he became a hero