Saitama and Genos are out shopping when they come across G4, a demonic robot on a mission to eliminate King. Meanwhile, Sitch attempts to recruit various assassins and villains.
Garou issues a declaration of war on the Hero Association through terrifying means, Hellish Blizzard gives Saitama an ultimatum, and Genos decides to eliminate his master's stalker, Speed-o'.
Garou attacks the S-rank hero Tank top Master, his followers, and Mumen Rider. Garou continues his pursuit of attacking heroes. Saitama buys a wig to join a martial arts tournament after having a brief exchange with Garou.
Assigned to guard a VIP and his son, Metal Bat couldn't be less thrilled. But when the group is suddenly attacked all hell breaks loose. Meanwhile, Saitama has disguised himself as Charanko in order to enter the "Super Fight" martial arts tournament.
Metal bat fights Garo. A lot of monsters surface around multiple cities and it is difficult for all the heroes to fight them. Meanwhile, Saitama is at the tournament and Genos is in the audience.
Saitama continues facing opponents in the tournament. Genos receives a stress signal depicting that there are 5 monsters in City C and goes to kill them. Blizzard tries to fight a monster but she turns out be very strong.
As the Super Fight tournament heads for its grand finale, the Class S heroes battle to hold back the tide of monster incursions. Meanwhile, Atomic Samurai is setting in motion a plan of his own.
Goketsu, the first Super Fight Tournament champion, arrives in the stadium. Having now become a monster, he's aiming to force the Super Fight competitors to turn into monsters themselves. When several do, it's up to Suiryu to take them on alone.