In the manga One-Punch Man, the Hero Association’s highest official rank is S-Class.
The Hero Association grades registered heroes into four standard classes: C-Class, B-Class, A-Class, and S-Class. S-Class is reserved for heroes considered exceptionally powerful and capable of dealing with major threats independently. The ranking system is separate from the story’s threat levels, which describe monsters and disasters rather than heroes.
Saitama is initially placed in C-Class after passing the Hero Association’s examination, despite possessing extraordinary strength. His low ranking reflects his poor written-test result and the organization’s limited understanding of his achievements. He gradually rises through the classes as his actions become harder to ignore.
The rank is sometimes confused with “God,” which is a disaster-level designation, not a hero class. One-Punch Man began as a webcomic by the artist ONE. Yusuke Murata illustrates the serialized manga remake, which expands and redraws material from the original version.