Yukiteru Amano is a loner who spends his time writing in his mobile diary and talking to an imaginary friend, Deus Ex Machina. However, one morning, he finds his diary entry for the day has been filled in already. Stranger yet, the events portrayed in the diary start coming true

Yuki is trying to figure out the reason behind Yunos Future Love Diary when a woman named Uryuu Minene interrupts him. She quickly identifies him as the 1st and announces that she is the 9th and that the 1st will die

Having escaped with their lives from the 9ths death trap at the school Yuki and Yuno find them selves in an alliance with the 4th diary holder Detective Keigo Kurusu. The 4th asks the two of them to spend the day together at an amusement park to act as bait for the 9th who continues to elude the 4th and his detective diary. At the end of the day Yuki uncovers an unsettling secret about Yuno and the 9th may have fallen into a trap set by someone other than the 4th

Yuki is unable to tell anyone about the corpses he saw in Yuno's house, fearing she will find out through her diary. The next day, Keigo, Yuki and Yuno visit the Sacred Eye cult, where Uryu is being held prisoner. The cult's leader, Tsubaki Kasugano, is the holder of the Clairvoyance Diary, a scroll which tells the future as seen by her followers and has foretold her death by the end of the day

Yomotsu appears before the fleeing Yuki, Yuno and Tsubaki with four hypnotised cult members dressed like him. Yomotsu explains that his Righteous Diary led him to infiltrate the Sacred Eye cult and that he intends to blow himself and Tsubaki up using Uryu's bomb. Having learned from Keigo that Yomotsu is blind, Yuno manages to find and kill him

Knowing from her diary that Yuki's mother is coming home from abroad, Yuno breaks into Yuki's house with the intention of introducing herself to Yuki's mother. Despite Yuki's efforts, his mother and Yuno meet and take a liking to each other. That night, Yuno reveals to Yuki that her diary predicts they will "come together" on a certain date and tells him she will do anything to make sure that future comes to pass

Reisuke tries several times to kill Yuki and Yuno, but the two of them thwart his attempts, soon realizing he is a diary owner. Yuki starts searching for Reisuke's diary in vain, while Yuno insists killing him would be faster. While chasing Reisuke with a hammer, Yuno ends up injuring Yuki's mother instead

Deus calls a meeting of the eight surviving diary holders, one of whom requests to transfer his diary's ownership. Two weeks after Reisuke's disappearance, Yuki and Yuno transfer to a new school, while a series of brutal murders has been terrorizing the area. After school, Yuki and Yuno sneak in one of the crime scenes with Yuki's classmates Hinata, Mao and Kousaka

In a flashback, Hinata receives the Breeder Diary from her dog breeder father, who wants her to eliminate Aru. When Hinata demands Aru's diary, he challenges her to guess which hand he's hiding a coin in, with his diary as the forfeit. Despite using Yuki's diary, Hinata loses and has to release Yuki

While making bombs for Keigo, Uryu remembers the time she was captured by a detective called Nishijima while confronting the serial killer diary holder. Although they develop a rapport as they evade and defeat the killer, Uryu ends up knocking Nishijima out to escape. Aru sets up Yuki and Yuno on a date to a bridal fair, where they meet Keigo's wife, while he investigates Yuno's house

In a flashback, Keigo forms an alliance with Uryu, promising to stop pursuing her and asking her to take care of his terminally ill son if he is eliminated from the Survival Game. Yuki and Yuno get arrested and brought to Keigo. In the interrogation room, Keigo forces Yuki to play a rigged game of Russian Roulette with his service revolver

While the police surrounds the hospital, Uryu takes Keigo's wife and son hostage and tries to bargain with him. However, Keigo is convinced the only way to save his family is to win the survival game and refuses to negotiate. Yuki gets captured by the police, but as Keigo takes hold of him, Yuno appears, holding a grenade

When Deus realises that his assistant, Murmur, manipulated events to hasten Keigo's elimination, she claims she wants the game concluded before he has to "retire" and challenges him to a wager on the winner of the survival game, with her picking Yuno and Deus betting on Yuki. Yuki and Yuno go on a stargazing trip, but Yuno alters their destination along the way. Worried about Yuki's safety, Aru contacts Nishijima and they manage to narrow Yuki and Yuno's location down to a run-down holiday resort, enlisting Hinata, Mao and Kousaka to search for them

Aru talks to Yuno through her surveillance feed, revealing he dug up three corpses from her garden, two of which had recently had their skulls removed. When he threatens to give this information to the police unless she releases them, the stress causes Yuno to alter her memory again, rendering negotiations moot. As Kousaka uses his cell phone to post his will in his blog, it is apparently turned into a Future Diary by the Eighth diary holder, who adresses him as an "apprentice"

Aru deduces that the Eighth's diary is a server hosting and sending predictions to the blogs of her apprentices. When Yuki's diary predicts an attack by three of them, Aru has him moved to Kousaka's mansion. His plan is to lure the apprentices in, then deactivate the area's cell phone tower, severing their connection to the Eighth's server

Aru deduces that Marco and Ai have not destroyed Yuki and Yuno's diaries because they want to take advantage of the information they provide. In order to confuse them, he has Uryu feed Yuki false information. Yuki's father visits him in the hospital, but while Yuki's away, he searches the room for his cell phone

In a flashback, Marco and Ai are abandoned children who meet in the commercial tower, grow up in Kamado's orphanage and eventually fall in love. Yuki chooses to take Yuno's hand, while Marco and Ai run to the crumbling tower's roof with Yuki's father, intending to jump off with parachutes. Yuno catches up to them and once again tries to fight them alone, while Yuki hides and attempts to help her with his diary's predictions

In a flashback, Yuno is revealed to have murdered her parents, who used to discipline her harshly for failing to meet their standards. After she fell in love with Yuki, he became her sole reason to live. Yuki asks Deus to bring his mother back to life, but he reveals that he is dying and his powers have faded

The mayor of the city, John Balks, passes a motion to have Kamado's orphanage shut down. He then attends Deus' meeting, where Yuki and Yuno, having deduced his identity, expose him as the Eleventh diary holder. Uryu relays these news to Nishijima, who reveals he's been reassigned as Balks' bodyguard

Despite Aru's revelation, Yuki declares his trust in Yuno. Balks connects Kamado's server to HOLON, a supercomputer which holds user accounts of every citizen of the city, making them his apprentices. Uryu tries to attack Balks, but his diary lets him turn the tables

Yuki and Yuno wreak havoc, demanding that Balks release their friends and commit suicide. Balks locks himself in a vault belonging to Yuno's parents' bank, which can only be unlocked by himself, Yuno's parents, and the real Yuno. Uryu, reasoning that Yuki can no longer eliminate Balks for her, starts hunting him

Shocked at Deus' answer, Aru attempts to tell Yuki, but Deus stops him. Deus reveals that Aru is an entity created by him to observe and record information on the survival game and starts disassembling him, promising to spare him if he proves he has done anything out of his own free will. Aru succeeds when he reveals he had Kamado make his diary into an apprentice diary, wishing to change the future and save Yuki

With a small core being all that remains from Deus, Murmur proclaims herself his successor until his death and the end of the world on July 28th. Yuno reminds Yuki about her diary's prediction that they will "become one" on that day. As the days pass, Yuki eventually admits to himself that his friends were probably telling the truth

Yuno expresses her disgust at how this state of affairs prevents her and Yuki from ever surviving together. She states that since Yuki won't kill her, she will kill him and travel back in time again to meet another Yuki. Murmur shoves Yuki off a cliff, but he is saved by the sudden reappearance of Uryu, who displays powers similar to Murmur's

An ambulance arrives at Yuno's house together with the third Yuno's father. Although he is a much more caring man in this world, Yuno has to stab him when he starts getting suspicious of her. Uryu drops off Yuki and the third Yuno at the school and makes a phone call to this world's Keigo, forewarning him about his son's illness

After some hesitation at seeing the innocence of her other self, Yuno lunges at her, but she is stopped by her other self's parents. Meanwhile, the actions of Yuki and Uryu have caused a domino effect that has changed the future of almost every diary holder for the better. When Balks reads about his other self's death in Yuki's diary using his incomplete Watcher Diary, he calls off his partnership with Deus, who decides to cancel the survival game and find another method to determine his successor