Fat Gum's Team vs. Octo-Lover's Brigade

Tamaki Amajiki & Taishiro Toyomitsu vs. Octopus Protection Association is a battle fought between the hero Fat Gum & his intern Suneater against radical members of Octopus Protection Association.

Prologue
On the occasion of the Team Up Mission program, Tenya Iida and Momo Yaoyorozu go to the Fat Gum Agency, to do the program with the Hero and Tamaki Amajiki. Their first mission is to help a girl named Hime, who is looking for the hero who rescued her during the octopus villain riot, violent altercations carried out by radical members of the Octopus Protection Association and had to be suppressed by the heroes. However, the girl does not know the name of the hero and the description she provides is not very accurate, so Fat Gum and the students decide to check all the agencies that were involved in the octopus villain riots.

However, after spending hours visiting agencies and asking heroes, they fail to find the person who helped Hime. The girl is saddened by the idea of not finding her hero, but Tamaki reassures her and assures her that they will find him.

At that moment, a dark figure emerges from an alley with the intention of attacking them

Battle
The mysterious figure attacks Tamaki from behind, but he manages to dodge the blow that ends up hitting the sidewalk. While dodging, Tamaki grabs Hime and drives her away from danger, putting her in Momo's custody. The Fat Gum team find that the attacker is a member of the Octopus Protection Association, and six more members of the organization come out from the alley. They are leftovers from yesterday's riots and they are there to get revenge on heroes for got in their way the other day.

Tamaki quickly takes the lead and orders Tenya  to guide citizens and evacuate the area, and Momo to make something to protect him from the ink. Momo creates two blankets, one for him and the other to protect Hime. Tamaki also asks Fat Gum to help him in the fight by absorbing all the enemies’ attacks.

One of the rioters with an Octopus-like Quirk spits Tamaki ink several times to try to blind him, but Tamaki protects himself with the blanket. Another of the villains, one with a ammonoidea-like head, tries to kick him, but Tamaki bends down and ends up hitting Fat Gum in the belly, who has stood in front of Tamaki to protect him. The blow does nothing to him.

The rest of villains constantly attack Fat Gum, who endures his blows thanks to his Fat Absorption Quirk, absorbing the force behind enemies' attacks, until he accumulates enough energy inside. Seeing all the enemies surrounding Fat Gum, Tamaki uses his Quirk to turn his fingers into tentacles and catches all the villains, throwing them into the air, where they are all knocked out by Fat Gum with a single but powerful blow by releasing all the energy he had accumulated.

With this attack, all rioters are defeated and captured.

Aftermath
With his last attack, Fat Gum loses all his defense-fat, turning into his slender version. Seeing him with this appearance, Hime happily hugs him, because she has finally found the hero who saved her. To Fat Gum's surprise, the hero they've been looking for all morning was him from the very beginning. His slim appearance is so different from his fat one that even Iida and Momo have to ask him who he is.

With the case resolved, they return to the agency, where Hime thanks them for finding her savior and “prince”.