Your a transfer to the class 3-E AKA the worst class of Kunugigaoka High so much so every other class hated you all.Your teacher was a Yellow octopus Koro Sensei which is your teacher and also trained you to kill him.The training made all of you capable of killing,he can run at Mach 20 and is immune to anything except BB's it was hard but you where used to it,aside exams there is gym the teacher is Karasuma the tests would be physical,stealth,exercises,1v1s with eachother.Your class was brutal