Saitama vs. Pluton

Saitama vs. Pluton is a battle between Saitama and King of the Underworld, Pluton. It is also the final battle to take place in Season 1 of the anime.

Prologue
Pluton is first seen in Z-City, but has now appeared in Y-City. The King of the Underworld states that humans waste their existence in decadence and gluttony, littering the planet with worthless objectsHe continues to wreak destruction. He proclaims that they shall rot in the underworld that spreads below his snout. As he is walking, he is about to kill a child, but Genos saves the child before the building collapses over him. Pluton notices Genos and asks who the cyborg is. Genos states that there is a great man who is a hero for fun and a prophet. Pluton lifts his head when he notices something headed toward him.

Battle
Saitama already noticed Pluton and jumped towards the dragon-level monster's head, blowing it apart with a single punch and making Saitama the victor. Upon killing Pluton, Genos smiles and continues his statement by saying he is Saitama's disciple, surprising the child he saved.

Aftermath
Dozens upon dozens of gallons of blood spread across the city, as well as Pluton's intestines. Saitama looks at his steaming glove, frowning that he defeated Pluton with a single punch, and yells out "damn it!" to the sky.