Assassination classroom
(Book)

The night sky is forever changed when the moon is blasted into a permanent crescent. Confronting the governments of the world, a yellow tentacled monster boasts that it was the one responsible for the catastrophe and makes a peculiar demand: a teaching position at the prestigious Kunugigaoka Junior High School. Although the fate of the world now rests on their shoulders, the class has more personal issues to deal with. They don't believe themselves capable of success in daily life, let alone against a monster that surpasses the abilities of any human. But as the enigmatic creature—whom they dub Koro-sensei—educates them in both assassination and academia, they slowly find the courage to rise up and take aim at their target.,- From myanimelist.net.

Rated T+ for older teens. Contains realistic violence and suggestive situations.

Translated from the Japanese.