Secret time

Basically Gakushuu figures out about Koro-sensei after his only friend Ren dies from an experiment that Shrio conducts, and transfers to e-class to try and assassinate Koro-sensei for a secret revenge. I don't own assassination classroom or the pictures used. Will include some spoilers it you have not finished the anime, (I have not read the manga) hope you enjoy my first assassination classroom fanfic.