One-Punch Man, produced by Madhouse and broadcasted in 2015, with twenty-four episodes, has recently become one of the most popular anime. There is no filler content reported.
The Hero Association was created to fight monsters and bad guys. Out of all the heroes, Saitama is so strong that he can defeat any foe with just one punch! Nevertheless, this doesn’t leave him satisfied anymore as his power has gone unchecked for too long now. He’s been bored while other people have done entertaining stuff, like saving lives or fighting crime.
This is until a young cyborg named Genos approaches Taiki Village to help track down another cybernetic human killer called Metal Bat, who killed his entire family (including older sister Hinata)! A few days later, they meet again at City Z station near train tracks, where everybody congregates during night time hours.