Mumen Rider has just arrived at J-City and is talking on the phone with the Hero Association. He is told to rush to the emergency center. As Mumen Rider rides off to the shelter, he drops his phone. Saitama ends up picking the phone and talks to one of the Hero Association assistants. The assistant is initially reluctant to tell Saitama where the monster is, but after looking over Saitama's record, he changes his mind. The heroes at the emergency shelter are quickly defeated by the Deep Sea King. However, Genos soon arrives and starts fighting with the Deep Sea King.
Genos launches the Deep Sea King out of the emergency shelter, but also creates another large hole. Unfortunately, the Deep Sea King immediately recovers from Genos' punch and retaliates by attacking Genos when he was distracted by the crowd. The Deep Sea King is able to rip Genos' arm off and knock him towards a wall. Genos tells everyone to get out of shelter while he holds off the Deep Sea King. During their battle, one of the children cheers on Genos, this annoys the Sea King and causes him to launch a spit of acid at the child. Genos is just barely able to get in front of the spit in time preventing it from harming the child.