One-Punch Man Episode 9: Unyielding Justice

Saitama waits for the Hero Association's decision on whether to deploy him against the **Deep Sea King**, while **Genos** engages the monster in battle. Genos unleashes a massive energy attack that appears to defeat the Deep Sea King, but he lets his guard down, and the monster rips off one of his arms.

Genos instructs the civilians to flee while he distracts the regenerating Deep Sea King, holding his own until the monster spits acid at a little girl; Genos intercepts it, melting much of his bionic body and leaving him critically damaged and unable to stand. The Deep Sea King mocks Genos for shielding the child and prepares to finish him off, as her father drags her away.

**Mumen Rider** arrives on his bicycle and attacks the Deep Sea King to protect Genos, landing a punch before being grabbed by the arm and battered like a weapon until his sleeve tears, sending him flying. Undeterred, Mumen Rider rises repeatedly, grappling the monster despite being easily overpowered, as civilians gather to watch and the Deep Sea King grows bored.

The crowd cheers Mumen Rider on, but he is knocked unconscious; Saitama, now authorized by the Association for backup, catches him mid-fall. Saitama confronts the Deep Sea King, exchanges brief words, and defeats it with a single punch, killing the monster as rain begins to fall.

The townspeople praise Saitama and tend to the injured heroes, with Sonic reappearing elsewhere in town, mistaking the Deep Sea King's absence for flight. Later, Saitama receives fan mail revealed to be from Mumen Rider, who buys him dinner; Genos reflects on Saitama's choice not to take credit, vowing to intervene if it harms him.

In the hospital, Lightning Max and Stinger recover while reading newspapers, fleeing when **Puri-Puri Prisoner** arrives offering "Angel Shots"; he grows upset seeing himself labeled an "S-Rank Failure." Saitama is promoted to B-Class.