Assassination Classroom, Vol. 1 by Yusei Matsui

[Viz] When the misfits of Class 3-E get stuck with a smiley-faced, octopus-tentacled schoolteacher with bizarre superpowers, they discover they have a lot to learn… When the misfits of Class 3-E get stuck with a smiley-faced, octopus-tentacled schoolteacher with bizarre superpowers, they discover they have a lot to learn… Koro Sensei has already blown up the moon. He promises not to do the same to the Earth on one condition…that he be allowed to teach a certain junior high school remedial class for one year. In addition, he’ll allow the students to attempt to take him out at any time without retaliating. Whoever succeeds gets a huge cash reward from the Ministry of Defense. But now the students of Class 3-E are the only ones standing in the way of the destruction of the planet! Meet the would-be assassins of class 3-E: Sugino, who let his grades slip and got kicked off the baseball team. Karma, who’s doing well in his classes but keeps getting suspended for fighting. And Ok