One-Punch Man: The Hero That Doesn't Want Fame.
After Vaccine Man was defeated by Saitama, two heroes witnessed him killed Vaccine Man. The two random heroes reported this to the Hero Association. They decided to sent a S-Class hero to recruit Saitama to join the S-Class hero, but he refuses because he wasn't interested or not ready for recognition or fame, so they tried to beg him to be in S-Class but he still refuses, so they decided to put Saitama in C-Class hero, but in reality, he was actually an S-Class hero.
This is also a fic where Saitama uses multiple Serious Series techniques, lol.
(I admit, I love Saitama's serious techniques, even though they sound ridiculous and funny, they still sound pretty badass.)
Disclaimer: One-Punch Man belongs to the Creator, ONE.
