Future Diary (term)

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

Overview & Background
The Future Diaries are tools created by Deus and John Bacchus who sought a way to achieve further human evolution. The result of such project is 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, scroll 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 Holders, 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 of 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 Holder itself. Also if the diary is broken or destroyed, the user will die.

Despite the differences between the diaries, there are things that most of them have in common. One is that when a 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 Holders, entries in the diaries are changed as to cope with the changes done in the future, this especially in the cell phone diaries is known via a signature static sound. When this happens, an entry known as a Dead End may appear. This entry means that given the changes in the future if allowed, the Holder will be killed. Although a Dead End is not impossible to overcome, the chances to successfully do so vary a lot, 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 the Holder will be successful in his or her goals.

It appears that each diaries ability are also based on what the holder used to write about in their old diaries, example: Yukiteru's future diary can only tell what is happening around him, in his old diary he uses to write about the things that were happening around him. If this is true, then that means Yuno wrote about Yukiteru every 10 minutes, the Third might have wrote about his past victims, the Fourth wrote about his investigations, the Fifth may have wrote only 3 entries a day, the Sixth could have been writing about the cults activities, the Sevens most likely wrote about each other, the Eighth wrote about the orphans, the Ninth wrote about her actions and her plans most notably her escape, the Tenth most likely wrote about his dogs, the Eleventh Diary was special as it showed him the entries in all the other diaries, and the Twelfth wrote about the deeds he thought were righteous.

Though the main benefit of the diaries is their ability to tell the future. Some diaries have secondary effects that strengthen their usefulness even further. For an example, Twelfth's ability to hypnotize people and Tenth's to control his dogs. Instead of affecting themselves, the diaries connect them to others, an example the Sixth's seeing through the eyes of her cult, Eighth's ability to endow upon others Apprentice Diaries, and the Seven's ability to constantly monitor each other.

Diary Holder
A Diary Holder is a person capable of predicting the future via his or her Diary. Primarily, there are twelve Diary Holders who are candidates for Deus Ex Machina's survival game (Thirteen in the game, The 13th Diary Holder). However, it is possible to create Apprentices, where each individual receives a future diary as well. Also an interesting note, a diary holder is not necessarily a single person; for example, Seventh was actually two people with two identical diaries. Although diaries are meant for certain people, it is possible to temporarily transfer the diary ownership to another, allowing them to use their diary.

List of Diaries
The following is a list of the diaries used by the main characters and participants of Deus' battle royale.
 * The Indiscriminate Diary (無差別日記, Musabetsu Nikki?) : The diary used by the series's protagonist Yukiteru Amano also known as The First. It gives him the ability to read the details of his surroundings, be it present or future. This makes the diary balanced but it will not tell him anything about 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, which shows her entries related to Yukiteru on intervals of 10 minutes each. The diary will tell her everything about Yukiteru Amano, but nothing about herself unless it is related to Yukiteru, therefore when combined with Yukiteru's Random Diary, the two can make a fearsome combination that covers each other's weaknesses. This diary reflects her obsessive love for Yukiteru. 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 his victims will do, therefore he cannot 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 activities 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, which 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 until the next day for more entries. His diary may reflect his rather impatient and childish behavior since he is a child. It is a coloring book.


 * The Clairvoyance Diary (千里眼日記, Senrigan Nikki?): The diary used by The Sixth, Tsubaki Kasugano, which 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 will not 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 reflects 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, which allows her to create Apprentice Diary Users (see below). This means that while she can give anybody the power of a Future Diary, she cannot 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 laptop.


 * 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, whose entries reveal any escape route available to her, if any (where to go, how long to remain hidden, etc.). This means it will not 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, which 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 Uotcha): The diary used by The Eleventh John Bacchus, which 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, however, he cannot know the degree of truth of those entries, therefore he is vulnerable to misinformation and does not receive any Dead End flags. It reflects him as the creator of the diaries. It is a tablet.


 * The 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, which allows him to listen to his own righteous deeds that he will do in the future and it seemingly allows him to hypnotize people. It reflects him as the just vigilante he claims to be. It is a recording device.


 * The Video Diary: (Game Only) The diary used by the Thirteenth, Azami Kirisaki, which is a digital video camera that allows her to visually record the future and shows her what she will record on her diary.

Apprentice Diary
Along with the Future Diaries is a special type known as the Apprentice Diaries. These 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 Holder itself in connection to the server. Apprentice Holders 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 these Holders, 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 Apprentice Diaries also reflect their Holders, on particular traits. Although some Holders are not really given any background some examples are seen to follow this rule.


 * If the Diaries are broken, the Holders 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 interrupted, 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 Bacchus and The Seventh.


 * It is an alleged suggestion that 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 necessarily the Eighth's.


 * Although never seen, it is suggested that once given, they cannot be taken back.

The following is a list of the known Apprentice Diaries and their users if known:


 * 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: Used by Ta-kun. By making a connection with a diary, it is capable of copying its abilities, including 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 successes.


 * The Neo Kosaka King Diary: A replacement of the previous. This one predicts the successes 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 Ryuji Kurosaki, John Bacchus' Secretary. Its entries are actions by John, serving as a shield whenever John'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.

Unnamed Apprentice Diaries are seen used by Sakurami citizens after John Bacchus connects the city's phones up to Kadamo Ueshita's diary - including a terminally ill man's diary telling him he will die soon, a stock manager discovering the next day's prices, and a young boy's telling him what food his mother will cook for dinner.

Scrapped Prototypes
Deus at one point reveals that before the game was hosted, he and John created a few prototypes. As of the events in the series, they are never used by anybody and were therefore scrapped, but have been named and detailed. They are as follows:
 * The Radar: Predicts ones surroundings. A likely prototype version of Yukiteru's Random Diary.
 * The Searcher: It predicts certain people's actions. A likely prototype version of Yuno's Yukiteru Diary.
 * The Supplier: Can provide others with Diaries. A likely prototype version of Kamado's Blog Diary.
 * The Organizer: Gives details about an organization. A likely prototype version of either Tsubaki's Clairvoyance Diary or Karyuudo's Breeder Diary, perhaps both.
 * The Watcher: Initially a prototype, it was decided that John would use it in the game. It allowed John to see the entries of other diaries, which could easily be tricked by manually rewriting the entries.

Future Diary -Another:World-
In the Drama series, the diaries work mostly the same, save for few differences: The following is a list of the known diaries in the drama series: The following is a list of diaries that are not part of the survival game:
 * The diaries are all cellphones provided by the Chronus Company, and possibly by Deus.
 * All the diaries are equal in appearance.
 * Dead End entries have two phases, the first one in which the entry appears in a red colored background. The second phase starts so as long as nothing is done to prevent the Dead End and instead the future follows its normal course. When the Dead End's conditions start to be met, a countdown is shown next to the entry, revealing how long the Holder has before being killed. Deus reveals the only way to evade a Dead End is to kill someone else. It is said that if the countdown reaches 0 even if nobody does anything, the person will die, although this is unknown as any chance has been interrupted by the death of another Holder.
 * The diaries have different noises depending on the diary when entries appear, however the overwriting of an entry by defying the future is similar to that of the anime series.
 * The Perception Diary (知覚日記 Chikaku Nikki): Used by Arata Hoshino. It works like Yukiteru Amano's Random Diary. It gives him entries about everything he will see or hear, but say little to nothing about himself. They vary in time intervals and can predict things that will happen very soon to later events. It reflects how he accepts everything as the way they are.
 * The A-kun Diary (新太君日記 Arata-kun Nikki): Used by Yuno Furusaki. It works like Yuno Gasai's Yukiteru Diary. It allows her to predict everything about Arata, but nothing about herself unless it is related to Arata. It is hinted that it also gives details of his past, although it is unknown if this is due to the diary or plain stalking. It reflects her obsessive love for Arata.
 * The Trust Diary (信頼日記 Shinrai Nikki): Used by Megumi Fuwa. The dairy will tell her about people or events she may or may not trust. Ironically, she does not seem to trust much in her diary. It reflects her constant distrust of people.
 * The Murder Plan Diary (殺人計画日記 Satsujin Keikaku Nikki): Used by Yousuke Okuda. It works like Takao Hiyama's Murder Diary. It allows him to calculate the success chance of a plan designed to kill his victims to choose the best course of action. Presumed to range from 0%-100% with the highest ever seen is an 87%. Even the "best" chances are so far not fail-safe as they have a margin of failure, and can even give him a Dead End with even a high success chance. It reflects him as an intelligent serial killer.
 * The Evidence Diary (証拠日記 Shōko Nikki): Used by Kinjiro Hagito. It works like Keigo Kurusu's Criminal Investigation Diary, it shows entries about all the evidence he will find in a crime scene and get hints to solve the crime. The diary will only activate when he gets to the crime scene. Since it only shows entries about a crime scene, his diary won't tell anything about himself. It reflects him as the detective of the police.
 * The Action Diary (行動日記 Kōdō Nikki): Used by Tohru Kibe. It works like John Bacchus' Watcher Diary. It gives him entries about the actions of the diary holders. The profiles of the other diary owners are also present on Kibe's laptop and computers. It reflects him as the creator of the future diaries.
 * The Description Diary (説明日記 Setsumei Nikki): Used by Haruna Okie. It gives her a full description of people and/or events related to her that will happen. It can predict a lot in advance. Her diary apparently did not start until halfway through the game, although she reveals this to be a lie. It reflects her trend to judge people.
 * The Revelation Diary (発現日記 Hatsugen Nikki): Used by Rui Moriguchi (only in the second survival game). It gives him entries about events he will find out and/or is not aware of. It reflects his clever personality.
 * The Family Diary (家族日記 Kazoku Nikki): Used by Kurou Hoshino. It works like Tsubaki Kasugano's Clairvoyance Diary. It predicts what happens to his son and wife. However, it won't predict anything about himself unless is related to his family Revealed to be a lesser model of the Future Diaries made by Kibe. It reflects his great love for his family.
 * The God Diary (神様日記 Kamisama Nikki): Used by Deus and the winner of the survival game. It allows the user to control the virtual reality of Olympia and is allowed to be granted one wish with it. It is the only diary that does not predict the future. It reflects it as the god of Olympia.