One Punch Man - Season 1 (2015)

A group of Bald thugs use body armors to terrorize rich people. Sonic Speed, a hired ninja fights them. Unfortunately he meets with Saitama who is also a Bald.

Determined to get a little recognition, Saitama decides to become a pro hero, but first, he must pass the Hero Association tests and become a full-fledged member.

To remain on the "Hero" list Saitama has to show some activity in every week. Currently the City Z is defined as the 'ghost town'. Heroes are gathered together to find out whats going on.

A giant meteor threatens to destroy City Z. All S-Rank heroes are called to City Z to destroy the meteor before its collision.

Several Sea Folk appear and begin attacking citizens. They are easily defeated until The Deep Sea King appears and defeats many heroes including an S-Class.

The fight with the Deep Sea King concludes and Saitama and Genos reflect on it as well as Saitama's promotion to B-Class.

Saitama and all class S heroes are gathered together to be informed of an imminent extremely danger threat.

An alien conqueror lands in a spaceship to conquer the Earth during the S class heroes meeting.

Saitama takes on the alien leader in epic battle as the S class heroes fight the alien warriors and destroy the spaceship.