you were starting to fail to the exams of your school due to the assence of your parents (death or neglecting your choice) so your school had to send you to the section E, saying the truth, the government, knowing your phsicology and ability to manipulate choose you to come to section E sayinghtat it's because you didn't go well to school

when you first got there you were a bit surprised by the small structure who should be the school, but only 1 class was there so it's kinda obvious it was a small structure, but you didn't really mind, so you got in, when you did the teacher was strange it was like a yellow octopus with a circle head with a smile, you didn't laughed but it was very hard, then he said

Koro-sensei: "we have a new student introduce yourself"

when you were about to introduce you noticed a red-heared boy and a light blue-haired done, were they Nagisa and Karma..? You culdn't believe it but you shook it off and introduced yourself