Yukiteru Amano's phone diary becomes a survival tool when he and his classmate Yuno Gasai are drawn into a deadly contest. Both possess diaries that reveal future events, and they must use those predictions to stay alive against 10 other contestants. The winner will succeed Deus Ex Machina, the god of time and space.
Until then, Yukiteru had known Deus as one of the supposedly imaginary companions he spoke with despite having no friends at school. A shy middle schooler, he routinely recorded his daily activities on his phone. When entries began appearing before the events they described, he initially dismissed them as coincidence, then took advantage of their accuracy. Discovering Yuno's similar diary led the two to join forces against a strange pursuer. Only afterward did Deus explain the survival game and the role their phones, now called Future Diaries, would play.
