Brother... (karma Akabane X Reader) - Oh Wow

This is a story based on the anime Assassination Classroom, both season 1 and season 2. As the title states, this is an x reader which means that the protagonist of this story is none other than you.
In this story you used to be an assassin before your 'big brother', whom you left Britain to live with in Tokyo, got taken away (your big brother is the original 'Reaper' but you're not blood related, just very close), after this, you developed insomnia and a slight twitch which meant you couldn't focus on your studies in your new school, Kunugigaoka. As you couldn't focus in your studies, you got sent to E class; the end class, the class of failures, the class of delinquents... but a certain red head catches your eye.