Saitama and Genos track down an evil scientist who wants to know the secret to Saitama's power.
All Episodes - S01
EPS01
Saitama is a guy who is a hero for fun. After saving a child from certain death, he decided to become a hero and trained hard for three years. Though he's now so strong he can defeat any opponent with a single punch, lately he feels as if, in exchange for overwhelming power, he's lost something even more important. Written by Minhaj
EPS02
Genos, a Cyborg who is seeking Justice fights with a Mosquito Monster along with Saitama.
EPS03
Saitama and Genos track down an evil scientist who wants to know the secret to Saitama's power.
EPS04
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.
EPS05
Saitama and Genos find out about the hero registration and both took the tests to certify. Genos got S(Special) and Saitama got C grade. Meanwhile, Genos became the disciple of Saitama and learned about the power of saitama's punch on a training session. Written by Imtiaz_Emu
EPS06
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.
EPS07
A giant meteor threatens to destroy City Z. All S-Rank heroes are called to City Z to destroy the meteor before its collision.
EPS08
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.
EPS09
The fight with the Deep Sea King concludes and Saitama and Genos reflect on it as well as Saitama's promotion to B-Class.
EPS10
Saitama and all class S heroes are gathered together to be informed of an imminent extremely danger threat.
EPS11
An alien conqueror lands in a spaceship to conquer the Earth during the S class heroes meeting.
EPS12
Saitama takes on the alien leader in epic battle as the S class heroes fight the alien warriors and destroy the spaceship.