Lennon is your classmates, he is a secret murderer who is sent by people who is hate your family. Lennon is have many target in your class, times by times 3 of your classmates is kill their own self.

you think they are depressed and decide to die but you feel kinda weird about this, so you comes to the school at night.

you found a paper written 'run or die'. and you heard a sound of footsteps on your back, you look at your behind and see that's a boy with a mask and he is holding knife in his hand. (tbh that is Lennon).

you feel a chill running down from your back when the cloud is pouring. you doesn't know what should you do in that condition. so you decided to run, and yes he is chase after you.