あらすじ
This psychological thriller, based on the manga written and illustrated by Sakae Esuno, is about Yuki, a loner who's not very good with people. He prefers to write a diary on his cell phone and talk to his imaginary friend, Deus Ex Machina – The God of Time and Space. However, Yuki soon learns that Deus is more than a figment of his imagination when he makes Yuki participate in a battle royale with eleven others. The contestants are given special diaries that can predict the future, each diary possessing unique features that give it both advantages and disadvantages.
あらすじはAniListより（英語）。