Quick Summary: Originally a manga series, this was adapted for an anime with Funimation. Here is a quick quote from theanimenewsnetwork.com
Yukiteru Amano (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.
The genre for this anime I would classify as: action, drama, horror, psychological, and romance. This is not an anime for people who are squeamish about blood or violence, because both are abound. This anime makes good use of modern day connections and attachment to technology, every future diary hold has a cellphone that is attached to them. Each “User” in this game has a cellphone with a different type of use. I don’t want to give anything away about the characters or plot, but to give a few examples, one phone tells the actions of a single individual that is not the User while another will show the best path to take for escape in an emergency situation.
Each “player” in this game is generally called by their number rather than name. This is because no one knows who they other users are, when all together they are seen in shadow, which makes the game that more dangerous. For the most part you stay with the main character Yuki, though you learn a lot about the other characters in the story when it diverges away from him or as we go along with him in this dangerous game. Not all the focus in on the “Users” either, little by little you learn more about Dues Ex and his minion and how they play a role in this entire thing.
With plenty of twists, surprises, and strange events this anime is one that will keep you guessing and keep you on the edge of your seat. It came out quite a while ago, so there are plenty of site that offer streaming. I believe Hulu may even have it up available for viewing (or at least did at one point I know). It is an anime where once you finish it, you’ll want to see it a second time through to see how everything connects and putting the many, many pieces of the puzzle together.
Highly recommended for those who like shows that have a lot of cliff hangers, don’t mind violence, and strange-strange characters.