Future Diary is a Japanese manga series written and illustrated by Sakae Esuno. It was serialized in Kadokawa Shoten's Shōnen Ace between January 2006 and December 2010, and has been collected into 12 tankōbon volumes. The plot depicts the Diary Game, a deadly battle royale between 12 different individuals who are given "Future Diaries", special diaries that can predict the future, by Deus Ex Machina, the God of Time and Space, with the last survivor becoming heir to the universe.

Kadokawa Shoten (角川書店), formerly the Kadokawa Shoten Publishing Co., Ltd. , is a Japanese publisher and division of Kadokawa Future Publishing based in Tokyo, Japan. It became an internal division of Kadokawa Corporation on October 1, 2013. Kadokawa publishes manga, light novels, manga anthology magazines such as Monthly Asuka and Monthly Shōnen Ace, and entertainment magazines such as Newtype. Since its founding, Kadokawa has expanded into the multimedia sector, namely in video games and in live-action and animated films.