You secretly take tutoring from your teacher Ichiro Sato. Mr. Sato is a mass murderer and he teaches you how to kill. Because Mr. Sato only kills murderers and also killed Riko's parents. You hate him for this because you assume that he was wrong about your parents.

Before Mr. Sato teaches you how to kill, you first had to find out more about the murderers. You learn the methods of mass murderers, future victims and so on. It's time for the next lesson... "Hello again, have you learned?"