The second season of Ansatsu Kyoushitsu. 
 
The students return as school is back in session for the second semester. Following their exploits on the island during summer vacation, Class 3-E continues to sharpen their blades with their sights set on their teacher, the slippery Koro-sensei. They have more to worry about than just their teacher, however, as enemy assassins, both old and new, are out for the increased bounty on the octopus' head. 
 
Moreover, their rivals in Class A, as well as Kunugigaoka Junior High's fearsome principal, stand to block Class E from achieving academic excellence. With all of these obstacles opposing them, the group must continue to work together in order to overcome their foes and accomplish their goal of successfully assassinating their teacher.

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 Okuda, who lacks both academic and social skills, yet excels at one subject: chemistry. Who has the best chance of winning that reward? Will the deed be accomplished through pity, brute force or poison...? And what chance does their teacher have of repairing his students’ tattered self-esteem?
 
(Source: Viz Media)
 
Note: Includes 7 extras and the one-shot "Tokyo Department Store War Journal".

Nagai