The entire joke is that these characters are too competent at being heroes for a show this stupid, and the show knows it, every setup is a Dragon Quest parody that collapses the second actual class dynamics touch it. Chibi art style keeps them recognizable while letting the comedy breathe, and the self-aware video game logic means nothing needs to make sense as long as the bit lands. This is comfort food for fans who just want to spend more time with these people doing ridiculous things in a world designed to fall apart.

Koro-sensei is the Demon King in this fantasy world, and the students of class 3-E are the heroes meant to bring him down. At Kunugigaoka Magic School they study swordsmanship and sorcery, and their assignment is to kill their own homeroom teacher. To boost their odds, the class hunts down three powerful warriors, Karma Akabane, Itona Horibe and Ritsu, who end up joining them. The job stays close to impossible, since other parties also want the Demon King dead. Oddly enough, the one training the students is their target himself. Nagisa Shiota and his classmates appear as chibi magic students in this comedic spinoff of Ansatsu Kyoushitsu, adapted from the spinoff manga and picking up from the earlier film short. Fans of the original who enjoy silly takes on adventure tropes will find the familiar cast in a very different setting.