One punch man one a comic about figthing style and powers showing your skills to prove to the super heroes class.A comic were the heroes are supposed to defend the city's like A-city, B-city, Z-city, S-city, and M-city they have to level up their rank to kill better enemies and get respect and famous.
Saitama the main character in the series he's one of the strongest characters in the anime, Saitama and Goku always get compered. And he used to be a normal guy with a job and doing the same routine but one day he saw a kid getting bullied by a crab and he decides to save the kid from him and after that he found a purpose to his life he lives in city-z a city were theres not much happening one day Saitama got bald and saw he got powers and supper strength after training for 3 years and doing normal exercise after he notice he was bald and got super strength and he kept it as a secret.But than he notices a mosquito and he hates them so he was like crazy following the mosquito to kill it and the mosquito was goin to a villain that was controlling them and was stealing the blood from them so before saitama got there Genos the cyborg got there first and started fighting the villain she was a woman so Genos started throwing fire to quill the mosquitos but he didn't realize that she heals every time she gets blood from a mosquito so he decide to use all his power because he knew he got no chance to kill before he auto destroys himself and explote saitama gets there chasing the mosquito to kill it, than he realizes that the mosquitos were being ordered to get the people on the streets and steal all of their blood but before they could do that saitama was so mad that she brought all of the mosquitos and when the woman realize its a 2v1 she uses all of her power and when she run to Saitama, Saitama was ready and with 1% of his power he kill her.So Genos and Saitama meet for the first time and they become friends.