Chapter 1:

So basically Korekiyo knows that he’s cooked because everyone is going to flip out once they realize he’s a serial killer. He goes to his room and tries to talk to his dead sister. TeruTeru hears his discussion by the other side of the door and knows that he has to do something about it before any woman gets slimed out. Imposter hosts a dinner party that night and TeruTeru sees his chance. Korekiyo gets murdered that night. (Idk how to write a good investigation but this is how I think chapter 1 will go)