The third season of One Punch Man. 
Saitama is a hero who only became a hero for fun. After three years of "special training," he’s become so strong that he's practically invincible. In fact, he's too strong—even his mightiest opponents are taken out with a single punch. Alongside Genos, his faithful disciple, Saitama performs his official hero duties as a member of the Hero Association. 
One day, monsters claiming to be from the Monster Association suddenly appeared, taking a child of Hero Association executive hostage. The S-class heroes gather and plan a raid on the Monster Association hideout to rescue the hostage. Meanwhile, Garou, a "human monster" who was taken by the Monster Association during a battle with the heroes, awakens in the Monster Association hideout. 
(Source: EMOTION Label YouTube Channel Description) 
Note: Excludes recap episode that aired a week before regular broadcast.

Shueisha

J.C.STAFF

Action

Adult Cast

Comedy

Parody

Seinen

Super Power

Casts: Furukawa, Makoto, Hayami, Saori, Ishikawa, Kaito, Midorikawa, Hikaru, Onosaka, Masaya, Sakurai, Takahiro, Tsuda, Kenjirou, Yamaji, Kazuhiro, Yasumoto, Hiroki, Yuuki, Aoi

Nonton Anime One Punch Man Season 3