Good choice of words, because his name is OP man - Onepunch man. It's a comedy about a guy who wants to be a superhero, so he trains like crazy to become strong, except he overdoes it and becomes so absurdly overpowered he can kill anything with a single punch. Hence the name. Unfortunately, that made the whole 'hero" thing boring as fuck, because all his fights end in about half a second and he can't really have the cool battles other heroes can, so he just casually goes about his daily life while all the other heroes are having cliche battles with the monsters. With the super moves and "I WILL NEVER GIVE UP" speeches and everything. Occasionally, he runs into one and just bitchslaps the monster into a fine mist. Also, it's kind of funny because he doesn't act like an anime character. Everyone else is charging up ultimate attacks and doing monologues about friendship and willpower and shit. Saitama punches people in the middle of their monologue. He punches them while they're charging up their big attack. He punches them before they can show their final form. He punches them before they can even finish saying their name. His secret move was kicking someone instead of punching them. His most powerful attack to date is called "Series of consecutive regular punches". He is physically incapable of giving a fuck.

give anything 3 episodes before judging it unless you have already