Yukiteru Amano

Background and Diary
Yukiteru sees his own life as if he were a bystander. His "Random" (No Difference) diary reflects that attitude. In a detached, neutral tone, the diary records the future changes in his surroundings every couple of minutes. This gives Yukiteru timely, detailed entries of the future around him and is perhaps the one of the most accurate diaries revealed so far. It is extremely versatile and useful in just about any given situation. Its only flaw is that nothing short of a Dead End will make the diary record anything about Yukiteru himself.

His relationship with his parents seems strained at best. His parents had divorced one year prior to the begining of the series and he still holds out hope that they will reconcile and be a family again. His mother is often away for fairly long periods of time due to her occupation and his father rarely visits him.

Personality
Despite his severe lack of social skills, Yukiteru, nicknamed Yuki, is a fairly normal middle school student who has gotten in way over his head in Deus' survival game. He is favored by Deus to win the game because of his ability to overturn grim, inevitable outcomes to certain victory. For that same reason, he is also viewed by the other diary holders as being the most likely to win the game, and is therefore the most dangerous player who must be taken out. Yukiteru possesses remarkable accuracy in throwing darts, which he practices every morning with several dartboards in his room. He prefers to eliminate the other holders by destroying their diaries utilizing his darts instead of using the simpler method of outright killing them with sharp, pointy objects; possibly because he is one of the few people who is actually sane. Even though Yukiteru was socially withdrawn at the beginning, he has decided to at least change the way he used to be by making some friends.

Despite being at odds with the diary holders, Yukiteru has overcome several dire situations by himself using his own wits and hidden abilities. In the final confrontation with the Fourth, he was able to change an unavoidable future made by his diary seemingly through mere willpower.

Deus' Game
The series begins with Yukiteru narrating his life and how he records everything in his life in a cellphone diary from a bystander's point of view. It is later revealed that he has two friends who he belives to be imaginary, Deus Ex Machina, the god of time and space, and his servant, Murumuru. On this particular day Deus asks Yukiteru if he would like to "play a game". Yukiteru remains silent and the next morning he discovers that his diary has gained the ability to predict the future for the next 90 days.

He then exploits the advantage of being able to predict the future to avoid several school hazards and scores number 1 on a surprise math test, all with an uncharacteristic air of confidence causing many to view him as a different person. This draws the attention of school idol, Yuno Gasai. Later that day he sees a startling entry in his diary, a DEAD END. He learns that he is to be killed by a serial killer he had heard about earlierr on the news and initially believes it to be Yuno who appears to know of the effecs of his Future Diary. He runs in fear of being killed but no matter where he foes he can't seem to shake off Yuno. He eventually escapes to an elevator in a building only for Yuno to break in at the last second while at the same time revealing that she too is a Future Diary holder. Yukiteru prepares to attack but Yuno grabs his wrist, pins him to the elevator wall, and...kisses him.

She then reveals to Yukiteru her "Yuki Diary" which simutaneously reveals her obsession of him. She informs him that the true serial killer, the Third was on his way to kill him on the 14th floor and instead sends the elevator to the roof. Yukiteru is scared but Yuno tells him that she has a plan. Meanwhile the Thrid is revealed to also be a Future Diary holder and possesses the "Murder Diary" which gives him the future locations of his next victims.

Yuno and Yukiteru escape to the roof of the building and lie on wait for the Third to arrive. As the Third checks his Future Diary in confusion, Yukiteru appears and throws a dart with pin point accuracy right at the serial killer's "Murder Diary" causing said killer to ripple and disappear from reality (i.e. die). Following this, he appears before Deus and begins to realize the nature of the "game". Yuno then hyperly expresses that she will protect Yukiteru which causes him to put on a panicked expression in response to her obsessive expression.

Later, Yukiteru follows Murumuru to Deus's lair and it is revealed that along with Yuno and Yukiteru himself, 10 other people have been granted Future Diaries by Deus Ex Machina. The mechanics of the game are finally revealed. The goal of the game is for the players to eliminate one another user their Future Diaries to compete for the prize of becomind the successor of Deus Ex Machina. With the Third's death, only 11 remain and all of the other Future Diary holders (with the exception of Yuno) believe the First (Yukiteru) to be the most dangerous among them and resolve to take him out first. However, the Fourth openly declares that he will protect him.