Future Diary (term)

A Future Diary, is the main tool of the series and its namesake. It has the ability the future in several ways, it is mostly used by the participants of the battle royale set by Deus Ex Machina the God of Time & Space.

Overview & Background
The Future Diaries are tools created by Deus and John Balks who sought a way to achieve further human evolution. The result of such project are the Future Diaries, that can read the future, doing so in several ways and have several forms as well. The most common form is a cell phone, in which people write entries, however other forms exist, such as a picture book, or a recording device, etc.



As mentioned above, each diary reads the future in a different way, this as a result that each Diary reflects its users, in terms of personality, traits, desires, etc. For the sake of Deus's game, the Diaries have strengths as do have weaknesses, for example one can read the future about others, but not of oneself, this means that if an attack is aimed at one's person, that person will likely not know how and where will the attack come from, leaving a vulnerability that must be solved by the user itself.

Despite the differences between the diaries, there are things that are common in most of them. One is that when an user uses the diary to read and otherwise change the future in any way, this will have an effect in reality, changing what would have happened in normal circumstances. When this happens in "battle" amongst users, entries in the diaries are changed as to cope with the changes done in the future, this specially in the cell phone diaries is known via a signature sound (similar to a Noise found on televisions). When this happens an entry known as a Dead End may appear. This entry means that given the changes on the future, if allowed by, the user will be killed. Although a Dead End is not impossible to overcome the chances to do so successfully vary, although it is usually very difficult. Another entry that is known to appear (albeit only shown in one diary) is the Happy End an entry that shows when will the user be successful in its goals.

Diary Holder
A Diary Holder is a person capable of predicting the future via his or her cell phone. Primarily, there are twelve Diary Holders who are candidates for Deus Ex Machina's survival game. However, it is possible to create apprentices where each individual receives a future diary as well.

List of Diaries
The following is a list of the diaries used by the main characters and participants of Deus's battle royale.
 * The Random Diary (無差別日記, Musabetsu Nikki?) : The diary used by series's protagonist Yukiteru Amano also known as The First. It gives him the ability to read the future of his surroundings be it present or past. This makes the diary balanced but won't tell him anything of himself which leaves him open to certain attacks. Also the future on his diary is based on his viewpoint, that means on what he believes is true. It reflects his personality as a reclusive bystander. It is a cellphone.
 * The Yukiteru Diary  (雪輝日記, Yukiteru Nikki?) : Is the diary used by series's deuteragonist Yuno Gasai, it shows her entries related to Yuki on intervals of 10 minutes each. The diary will tell her everything about Yuki, but on herself unless it is related to Yuki, therefore if combined with Yuki's Random Diary, the two can make a fearsome combination that covers each other's weaknesses. This diary reflects her obssesive love for Yuki. It is a cellphone.
 * The Murder Diary  (殺人日記, Satsujin Nikki?) : The diary used by The Third, Takao Hiyama. It gives him entries on who his next victims are going to be, and where they are. However it does not tell him what will his victims do, so can't know which kind of attack will be used against him. It reflects him as a psychotic serial killer. It is a cellphone.
 * The Criminal Investigation Diary (捜査日記, Sōsa Nikki?): The diary used by The Fourth, Keigo Kurusu. It gives him details of criminal activies done within 90 days, and will tell him only of his own investigation. It reflects him as chief of the police. It is a cellphone.
 * The Hyper Vision Diary (はいぱーびじょんだいありー, Haipā Bijon Daiarī?) : The diary used by The Fifth, Reisuke Houjou, it gives him 3 entries per day, for morning, noon and night. While it may seem weak, it allows him to plan his full day to attack 3 times a day, however if all of them fail, he must wait the next day for more entries. His diary may reflect his rather impatience and childish behaviour since he's a kid. It is a colouring book.
 * The Clairvoyance Diary (千里眼日記, Senrigan Nikki?): The diary used by The Sixth, Tsubaki Kasugano, it shows entries of what her subordinates see, this means that she can have many entries and strategically direct her men. However if they are tricked, it is likely that she does not know, even if she does she won't know what is true. It reflects her as the leader of the cult, and also how she cannot see by herself. It is a scroll.
 * The Exchange Diaries (交換日記, Kōkan Nikki?): The diary used by The Seventh Duo, Marco Ikusaba and Ai Mikami. A pair of diaries that tell the future about each other, which allows them great teamwork as they can protect each other, the diaries are weakest when separated. It reflect the mutual love shared by the duo. It is a pair of cellphones.
 * The Blog Diary (増殖日記, Zōshoku Nikki?, "Propagation Diary") : Also translated as the Server Diary, is the diary used by The Eighth, Kamado Ueshita, it allows her to create Apprentice Diary Users (see below). This means that while she can give anybody the power of a Future Diary, she can read the future herself, therefore she needs somebody to fight on her stead. It reflects her loving nature as director of an orphanage. It is a computer.
 * The Escape Diary (逃亡日記<span class="t_nihongo_comma" style="display: none;">, Tōbō Nikki<span class="t_nihongo_icon" style="color: rgb(0, 0, 238); font: bold 80% sans-serif; text-decoration: none; padding: 0pt 0.1em;">?) : The diary used by The Ninth, Minene Uryu, its entries reveal any escape route available to her, if any (where to go, how long to remain hidden, etc.). This means in won't tell her anything to attack her opponents. It reflects her nature as a survivalist since a young age. It is a cellphone.
 * The Breeder Diary (飼育日記<span class="t_nihongo_comma" style="display: none;">, Shiiku Nikki<span class="t_nihongo_icon" style="color: rgb(0, 0, 238); font: bold 80% sans-serif; text-decoration: none; padding: 0pt 0.1em;">?) : The diary used by The Tenth. Karyuudo Tsukishima, it allows him to control dogs and see the future of them (if they found somebody, etc.). The greater the number the more concentration needed to control the multiple dogs in teams. It reflects his great love for dogs. It is a cellphone
 * The Watcher (ザウォッチャ Za Otcha): The diary used by The Eleventh John Balks, it allows him to peep in the entries of the diaries, even those from Apprentices, which allows him to know exactly what will his enemies do, and how to catch them off-guard, even to plan countermeasures. Since it only reads others, he can't know the degree of truth of those entries, therefore he's vulnerable to misinformation. It reflects him as creator of the diaries. It is akin to an iPad.
 * Justice Diary (正義日記<span class="t_nihongo_comma" style="display: none;">, Seigi Nikki<span class="t_nihongo_icon" style="color: rgb(0, 0, 238); font: bold 80% sans-serif; text-decoration: none; padding: 0pt 0.1em;">?): The diary used by the Twelfth, Yomotsu Hirasaka, it allows him to listen to evil deeds that will happen in the future and seemingly allow him to hypnotize people. It reflects him as the justice vigilante he claims to be. It is a recording device.

Apprentice Diary
Along with the Future Diaries is a special type known as the Apprentice Diaries. This diaries are specially provided by The Eighth's Blog Diary, as it has the power to make anybody (mostly users of electronic devices) a Diary User itself through connection to the server. Apprentice Users are introduced at mid-way through the game mostly when both The Seventh and The Eighth make their moves as most of the Apprentices seen are in fact orphans under the care of Kamado Ueshita. After the appearance of this users Deus himself tried to clarify some points regarding them and the game. Although he never clearly states anything about them some things are known as other are hinted, they are: The following is a list of the known Apprentice Diaries and their users if known:
 * The Apprentice Diaries also reflect their users, on particular traits. Although some users are not really given any background, although those who are follow this rule.
 * If the Diaries are broken, the users do not die, possibly because this is an extra power provided by The Eighth, rather than by Deus himself.
 * The Apprentice Diaries are vulnerable to jamming. If by any chance the connection between the diaries and The Blog Diary is interrumpted, then the diaries lose their power. They are the only known type of diary vulnerable to jamming as the normal diaries are seemingly immune to this effect as seen during the attack against John Balks and The Seventh.
 * Although not proven it is suggested they cannot become God. The orphans themselves state they want to make Ueshita God, but this does not truly prove whether they can or not, although given that their condition is special rather than by Deus, it is believed that it is impossible for them to become God, nor has any Apprentice User ever attempted this.
 * A regular participant can also use an Apprentice Diary.
 * Apprentice Diary users can join with whatever party they see fit, not necesarily The Eighth's.
 * Although never seen, it is suggested that once given, they cannot be taken back.
 * The Flirting Diary: Used by Ai Mikami. It allows her to check with which men she's going to flirt with. Mostly used to track targets.
 * The Brawler Diary: Used by Marco Ikusaba. It allows him to predict his opponents moves while brawling.
 * The Orphan Diary: Used by Orin Miyashiro. Unknown, but suggested that it predicts the future of Ueshita's Orphans.
 * The Copy Diary: By making connection with a diary, it is capable of copying its abilities, it can copy even normal Future Diaries.
 * The Kosaka King Diary : Used by Ouji Kosaka. It predicts his successful moments, mostly used to reverse a situation. It does not tell him of his failures therefore he can fail if he relies too much on his successess.
 * The Neo Kosaka King Diary: A replacement of the previous, this one predicts the successess of Kosaka and his friends. Suggested that it has the same weakness as the previous one.
 * The Friendship Diary: Used by Hinata Hino. It predicts conversations she will have with friends.
 * The Hinata Love Diary: Used by Mao Nonosaka. It predicts anything related to Hinata, working in a similar way like Yuno's Yukiteru Diary.
 * The Secretary Diary: Used by Balks's Secretary. Its entries are actions by Balks, serving as a shield whenever Balks's The Watcher is under misinformation.
 * The Detective Diary: Used by Aru Akise. It can read the entries of the Diary Users and predict their future.