The students in class 3-E are the misfits in their school, but their teacher is a powerful, tentacled extraterrestrial who has already damaged the Moon and threatens the Earth, and they have been assigned to assassinate him.

"Intramural relations are at an all-time low: Principal Asano wants to crush Koro Sensei's 3-E baseball team while Koro Sensei wants to avenge Principal Asano's sabotage of 3-E's midterms. Then the government sends in a new Special Forces operative--a ruthless father figure who tests Karasuma's combat coaching skills. You'll never guess which student does him proud! And when Koro Sensei digs a swimming pool to help his students cool off, they discover...

"Ever caught yourself screaming, "I could just kill that teacher"? What would it take to justify such antisocial behavior and weeks of detention? Especially if he's the best teacher you've ever had? Giving you an "F" on a quiz? Mispronouncing your name during roll call...again? How about blowing up the moon and threatening to do the same to Mother Earthunless you take him out first?! Plus a reward of a cool 100 million from the Ministry of Defense!...