Future Diary – Mirai Nikki is a Japanese manga series written and illustrated by Sakae Esuno. The manga was serialized in the Kadokawa Shoten’s Shōnen Ace between January 2006 and December 2010. Twelve tankōbon volumes were released in Japan.
Yukiteru “Yuki” Amano is a loner who spends most of his time writing a diary on his cell phone or talking with his imaginary friends Deus Ex Machina, the God of Time and Space; and Murmur, Deus’ servant. One day, Deus gives Yuki a special diary, mentioning something about a game. Strangely, Yuki’s new diary has entries in it spanning the next 90 days—entries about the future that come unnervingly true. Deus, the not-so-imaginary God of Time and Space, then forces Yuki to participate in a battle royale with eleven other people, each of whom also has a diary that can predict the future in some unique way. The rules of this “Diary Game” are simple: the contestants must try to find and kill all the other contestants before the world ends on Day 90, and only the last one standing can prevent the Apocalypse and become the new God of Time and Space.