They lure Third to the roof of the building, and when he draws his phone to check where they are, Amano punctures it with a thrown dart, killing him.
Deus brings the eleven remaining competitors into a vision and explains the rules: They must discover and kill each other.
Gasai knows this, because she also has a Future Diary. And she's been stalking Amano and writing his movements.
But that does mean she can help him avoid Third, the other diary user and serial killer who is after him right now.
Yuno Gasai, one of Amano's classmates, catches his eye. She's left behind a clay figure of Murmur.
How can she see what's only in his head?
Worse, his diary says he'll be caught and killed on the way home. Dead End.
When he wakes the next day, Amano sees that his diary has already been entered. With surprisingly confirmable details.
Deus tells him that the diary is his future, with that drawback: if it is destroyed, he will die.
Like Deus Ex Machina, God of space and time. And Murmur, his servant.
Deus asks if he wants to change his life, and sends him a message that contains the future. This will be a new game.
Meanwhile, the serial killer continues to stalk people who are out alone after dark.
We start with a grizzly murder.
Cut from there to school. Yukiteru Amano, our MC calls himself an observer. He doesn't participate in things, but obsessively keeps track of everything that happens on a diary in his cell phone.
He has no real friends, but rather, imaginary ones.