Ansatsu Kyoushitsu 2nd Season

Education, Slice of Life, Betrayal, Drama - these genres fit the full package in getting you hyped-up to watch this Anime non-stop! The main protagonist, Eikichi Onizuka, personalities are quite similar to the protagonist, Koro-Sensei, from Ansatsu Kyoushitsu anime; Despite the setting of the story, they are both comical from just their facial expressions alone to the insane actions they performed. They both share similar goals as to help students, striving them to walk the right path in life and giving the audience a sense of thoughts on their real life. Both teacher encounters disadvantage and challenging situation all for the sake of their students despite the consequences whether it's from an illogical or a logical standpoint. If you have the same feeling where you would want Koro-Sensei as a teacher in real life then this anime is the perfect anime for you to watch. This Anime will leave you a nostalgic moments for the rest of your life! read more 

Both have a school where students are trained to become stronger Also, both have a great comedy and charismatic characters 

-Both have special school, special students, and special/unique class (Class A in Boku no Hero Academia/Class E in Ansatsu Kyoushitsu). -Class A & Class E are more experienced than the other classes 'cause they have to face the real villains. -Strong figure as a teacher (All Might & Koro-sensei). -Both MCs are very alike that they want to follow their teacher's path. -Other characters are look alike too, like Bakugo & Karma (both are geniuses & violent), Uraraka & Kayano (cheerful & hardworking), Todoroki & Asano (their relationship with their father is kind of similar), etc.. -Competitions between the students that give the similar feeling. 

Both detail a necessary death. Both use the setting of "ordinary students". Both animes the characters learn something from what needs to be done. Different tones, different art styles. Similiar messages but delivered in different ways.  

If you liked the comedy in Angel Beats! you will likely enjoy Assassination Classroom. They both have teens trying to kill what they believe to otherworldly beings that they later form alliances with to take out the main threat. Aside from having very similar animation styles and lots of GUNS, they both have a similar formula of emotion+comedy to create an overall enjoyable experience. However the emotion in Ansatsu isn't as strong but the comedy is a lot better than in Angel Beats!. They're similar enough that you'll like them, but not so much that you won't be able to appreciate them for what they are. read more 

If you wanted a second half of the thing you are watching, Assassination Classroom has a good second half and no first half! It's a match made in heaven 

They are both very hilarious and so unique. It’s hard to find many good, well developed, non-cliché characters like the main characters in both of these. In every episode, you are sure to be laughing and I highly recommend watching them.  

Both anime makes people realize the importance of a certain someone . 

Both have characters, who are friendly like Nagisa or Tachibana, but they are both crazy and dangerous, when they really start. And both character (Tachibana and Nagisa) are mistaken by their gender. Naturally in both series its about "Killing" 

Both stories start with a lighter tone and seemingly less serious setting and evolve into very touching stories with serious heart-wrenching moments. These stories require that they be watched in order and fully to capture the experience. Don't forget to include the prequels/sequels. 

While Ansatsu is more focused on the various students of class 3-E denpa kyoushi is more focused on kagami the NEET teacher.The former cashes on the various neat tricks and comedy involving the daily intercourse of the teacher and the class the latter exploits the daily gimmicks of an otaku teacher.As a whole ansatsu is a more entertaining watch than otaku teacher. 

-Assassins trying to kill specific person to get reward -School 

Both have well done comedy and also a darker and deeper story with action and drama balanced.