Assassination Classroom, Vol. 21

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 Earth—unless you take him out first?! Plus a reward of a cool 100 million from the Ministry of Defense!