Class 3-E of Kunugigaoka Magic School is given a unique job one day: to assassinate their homeroom teacher, the Demon King Koro-sensei. To improve their chances of success, the class seeks out three of the most strong warriors—Karma Akabane, Itona Horibe, and Ritsu—who subsequently join their organization. Even with their assistance, completing the goal becomes an impossible endeavor because they are not the only ones seeking the Demon King's life. Koro-Adventure! sensei's The humorous exploits of Nagisa Shiota and class 3-E as chibi magical pupils are told. Trained by none other than their exact target, the pupils face difficult yet funny scenarios throughout the deadly quest of conquering the Demon King.