Chapter 1: Kill the Teacher

Nagisa Shiota is now 25 years old.

He is a teacher of failures by day and a deadly assassin by night.
He can not only conceal his presence but also make his presence very known because of what Bitch-sensei had taught him after graduating.

Soon, the class decides to visit their old classroom to see just how much everyone had changed over the past seven years after the death of their beloved Koro-sensei. But when Nagisa walks in, everyone is shocked. Why?