Nestled in the mountainous backdrop near the esteemed Kunugigaoka Middle School lies a rundown edifice where the troublemakers and outcasts of Class 3-E reside. Despite facing scorn from their peers, these students seem destined for academic mediocrity until a government directive thrusts them into an extraordinary mission: to annihilate their peculiar new teacher. This octopus-like being, known as 'Koro-sensei,' poses a grave threat to Earth after obliterating the moon and vowing to do the same to their planet by the upcoming March. Tasked with this daunting assignment, the students quickly realize that eliminating Koro-sensei is no simple feat. With his astonishing speed of Mach 20 and near invincibility to conventional weapons, the enigmatic professor presents a formidable challenge. Yet, paradoxically, he emerges as one of the most exceptional mentors Class 3-E has ever encountered. Guiding them to excel academically and hone their assassination skills, Koro-sensei believes in their potential to return to the main campus through their resourcefulness and unwavering determination. Amidst a journey of trials and discoveries, Nagisa Shiota and his classmates must swiftly uncover Koro-sensei's vulnerabilities as the world's destiny hangs in the balance.