"S-Class" (S級, Esu-Kyū) is the 29th chapter of the One-Punch Man manga series.
Bang is shown demonstrating his technique, Water Stream Rock Smashing Fist, to Saitama and Genos. He asks if they would like to give the technique a try. Unfortunately, they decline Bang's offer. Charanko is angered by their decline and challenges to fight them. Genos quickly defeats Charanko and states that he underwhelmed by the lack of skilled fighters in Bang's dojo. Bang explains that his dojo used to be full of skilled disciples, but they were all disabled by Garou, Bang's best disciple in the past. Bang further tells them that he expelled Garou after giving him a beating. Saitama acknowledges Bang's strength; a statement which Charanko would then scorn Saitama for because of Saitama's lack of knowledge of Bang's popularity.
After Charanko's constant talk, a Hero Association employee arrives at Bang's front door informing Bang and the others that an emergency summons has been issued to S-Class heroes. Bang, Saitama, and Genos leave for the meeting, while Charanko is left to watch over the dojo. At the headquarters, they are greeted by Atomic Samurai. Atomic Samurai declines Saitama's offer for a handshake, stating that he will greet him when he becomes a S-Class hero. Tatsumaki suddenly starts shouting at Saitama and belittling him only to have Genos inform Saitama that she is rank two in the S-Class and is an Esper. At the meeting, each S-Class member gives off their thoughts on the matter. Saitama asks for tea.
- Puri-Puri-Prisoner noticed Saitama and wonders who he is. He concluded that Saitama is Genos' sidekick, since he asked for tea, but was debunked when Saitama drank it himself.