Plot Summary:Yukiteru Amano (or Yuki) is a loner who never really interact with people and prefers writing a diary on his cell phone with his only companion being an imaginary friend named Deus Ex Machina, the God of Time and Space. However, Yuki soon learns that Deus is not a figment of his imagination but real when Deus makes him a participant in a battle royale with eleven others. Within this "Diary Game", the contestants are given special diaries that can predict the future with each diary having unique features that gives them both advantages and disadvantages. Within the next 90 days, the contestants must try to kill each other and survive until there is only one alive where the winner becomes the new God of Time and Space. In order to survive, Yuki tries to find allies and friends to help him with one of them being another diary user named Yuno Gasai, a girl who is madly in love with him. As the game continues, Yuki soon learns that not everyone can be trusted, not even Yuno, whose obsession to keep both of them alive no matter the cost terrifies him. Thus begins the game of life and death, where everyone wants to win, no matter the cost.