The 8th Diary Holder is a robot of some sortThere is no freaking way that thing is human.
Yuno will win the Survival GameOnce all but Yuki and Yuno are dead, she will turn the knife on him, and remake the world so she can be alone with her Yuki for eternity.
The 11th's Diary records the diary results of other diaries.It's broken enough for him to be the Big Bad. It fits with the name "Watcher Diary." It explains why Nishijima (who has no diary) is able to subvert his plans. And it explains why he wants to make everyone in the city a diary holder — nigh-omniscience!
The 11th's Diary is located in his mind because he has eidetic memory.This (and the nature of his Diary, as above) is how he knows exactly where and when the 9th will throw a grenade without looking in any visible Diary. It's also a major Game Breaker and will prevent him from being Diary-killed without taking a fatal head shot.
If Deus is God, then Murumuru is the DevilShe's a little imp who does things for fun (as opposed to the more purpose-driven Deus), favours the psychotic Yuno and maniacal 11th, alters Deus' plans in ways that seem to anger or frustrate him, and appears to have a devil tail.
The current Yuno is a replica Murumuru made of the original Yuno.Murumuru made Yuno 2.0 out of mochi, just like she did the fake body that she fooled Deus with, and implanted a copy of the original Yuno's mind in its head. This was done between the decision to hand out the Diaries and their actual delivery. Once the competition boils down to Yuno vs. Yukiteru, Murumuru will possess snack-food-Yuno, kill Yukiteru, and thus steal Deus's job.
The current Yuno is Wakaba Moe, the girl Yukiteru had a crush onShe liked Yukiteru back but rejected him in case the person in the bunny suit came after her some other time. Wakaba finds out it's Yuno and confronts her, which leads to either Wakaba killing Yuno out of self-defense (and giving birth to her yandere side) or killing her out of rage (which contributes to her already-existing yandere side). She then begins to impersonate Yuno to get closer to Yukiteru, since it would have looked awkward to go back to him as Wakaba after she rejected him publicly, and slowly develops into what she is now in case someone else tries to get in her way. The killing would have taken place soon after the initial incident (which was a year ago), and so Yuno would have plenty of time to decompose. [[supersecretspoiler: Jossed.]]
When Deus jammed his hand through Minene...
Akise is the real Yuno.This would explain why "he" is so interested in Yukiteru, as well as his actions against Yuno; she's the impostor who took "his" place and murdered "his" family.
When Yuno's diary said that her and Yuki would become one/be bound together......it meant it literally.
The current Yuno is the biological daughter of the Gasais.But she did not grow up to become the 'perfect' daughter the Gasais had desired, and so they kept her locked in a cage most of her life and adopted another child who fit their 'perfect' mold better. She grew up to resent the family, and thus killed her parents and the real Yuno, therefore taking Yuno's place. At the very least, it explains how she was able to open up the bank vault at the end of chapter 46.5.
The current Yuno gained an organ transplant from the real Yuno.That's a more mundane way to explain how she got into the bank vault in 46.5. Now the question is whether she is shown to be taking pills for this is not shown.
There is no real Yuno. That's because Gasai Yuno is actually two twins.This is why she got into the bank vault. The dead body is her twin sister. Their parents kept her locked up to make her perfect, and kept her twin out of the cage and treated her lovingly, to have comparison and feedback. That way they'd know if their treatment worked. Yuno escapes and kills the people who treated her that badly as well as her twin who had everything while she had nothing.
Akise is a White Hair, Black Heart involved in some kind of conspiracy or gambit since the beginning of the storyIt's obvious. He's already proved himself capable of outplaying three diary owners simultaneously. He's good at investigating and easily moves and finds stuff behind the main characters' (future predicting) backs. And he saves the 8th. He's got his schoolyard cronies together with her and he's plotting something with her and them in the latest chapter. He convinced her to take him to Deus. I predict some kind of plan to fool the future diaries. But this may just be because he instantateously gave me flashbacks to both Kaworu and Joshua.
Gasai Yuno is the winner of the game from a branching timelineThis would explain why there are two Gasai Yuno, both being shown as the real Gasai Yuno (from the body and from the bank vault). After winning the survival game, she leaped into the past (creating a parallel world; see chapter 48 for Deus's explanation), killed her past self, and took her past self's place. This would explain why she seems to know more than she should; however, her true motives are still shrouded in mystery.
Deus is actually Yukiteru who turned back time when he won the gameYukiteru in a past timeline won the game and became god, he then decided to turn back time. Turning back time probably drained him of most of his energy so he starting to deteriorate, so he had to start a new game to find a successor, thus creating a Stable Time Loop. The spin off series Mirai Nikki Paradox is a probably reset timeline that went wrong.
Yuno's second cellphone was stolen from the dead Yuno in Paradox
Murumuru has some sort of ulterior motiveShe seems to know far more than she lets on, has altered causality at least once, is pulling for Gasai Yuno for reasons unknown, and is shown at the end of Paradox possibly plotting something with some sort of duplicate Yuno. She seems too cunning and powerful to just be some minor Token Mini-Moe character, the question is, what is her plan and what are her motives? Will she turn out to be a Magnificent Bastard Big Bad who was playing Xanatos Speed Chess this whole time, or the Big Good (with an Omniscient Morality License, of course), or even the real Deus?
The series is Deconstructing Reset Buttons.At this point, the only thing keeping Yukiteru going is the idea that, when all is said and done, he'll be able to instantly fix everything. This will not be the case. What's more, he'll discover that this is Gasai Yuno's motivation: fixing something that didn't go the way they wanted the first time. In trying to "set things right", they've gone and broken down everything that stood in their way, and when confronted on this, will claim I Did What I Had to Do or Utopia Justifies the Means. In the end, the "winner" of the game will face a Pyrrhic Victory, standing as God of a wrecked and broken world, robbed of all the things that once made life worthwhile and holding a power that can't simply "quick-fix" everything. They will then be faced with a choice: try and 'correct' things anyway, even after seeing how horribly that went last time and knowing that it will have countless unforeseen consequences... or live with the broken world they brought upon themselves?
Yuno's plan is to eternally repeat the survival game so she can be with Yukiteru foreverSimilar to and related to the WMG above. Since returning to the past creates an alternate universe and lets the current one be doomed to destruction without a God of Causality, and it's shown that Yuno did this before, it seems Yuno would do anything to be with Yukiteru. Since they bonded during the Survival Game, it could be that she plans on going back in time to revive him and the other diary holders and start the game again to be with Yukiteru again. Then after winning again she plans on going back in time to revive him and the other diary holders and start the game again to be with Yukiteru again. Then after winning again she plans on going back in time to revive him and the other diary holders and start the game again to be with Yukiteru again. Then after winning again she plans on going back in time to revive him and the other diary holders and start the game again to be with Yukiteru again. Then after winning again she plans on going back in time to revive him and the other diary holders and start the game again to be with Yukiteru again. Then......you get the point. Either way it's obvious that Yuno would get along brilliantly with Beatrice, Bernkastel, and Lambdadelta.
Yuno Wasn't Always a YandereShe's just a cutie that's been broken so many times over by winning the game. Not just once, but like the Troper above suggested, several times over... perhaps she's even gone into the hundreds by this time around. Picture this scenario: The first time around, she and Yukki fell in love while trying desperately to survive, only for Yukki to either get killed or let Yuno win. Having won, but still grieving for her lost love, she uses her God powers to do the only thing that really makes any sense to her I can almost hear it... "Maybe... maybe I can bring him back to me...
Akise is Joshua.Come on! They're both White Hair, Black Heart boys running around and snooping into the enemy while filling the story with Ho Yay! Joshua even uses his cellphone as his psych!
The Survival Game is Sakurami's version of the Reaper's Game.Taking the above WMG further. It's entirely possible, since the Composer makes the rules. Deus is the Composer, Murumuru is the Conductor or some other Reaper, and the diary holders are all Players. It's not a contest to become God, it's a contest to stay alive. Instead of killing Noise, they have to kill each other. Wow, Joshua's version is tame compared to this.
Conversely, Akise is KaworuA White Hair, Black Heart boy who isn't really human who is the Gay Option for the main character? Obviously Mirai Nikki is taking place in Instrumentality, and Amano is really Shinji.
The game ends because Chzo gets involved.After all, we have confirmation that everything ends on July 28th.
Reisuke is related to the Houjous.They have the same last name and are involved in disturbing murders involving Yanderes and Religions of Evil. It speaks for itself.
Yuki will follow in first!Yuno's footsteps.Realizing that the only way to be with Yuno is to become god and go back in time to join her there, before things go wrong, he will kill her, and use his power to turn back time to the point when first!Yuno enters the second time stream, before she kills her double.
Yuki is an alternate version/reincarnation of Elwood.Apart from the fact that they look eerily similar (down to the hair style and fondness for beanies), both use throwing knives/darts for weapons. Both have lost family members and are relying on supernatural methods to resurrect them. Both are overshadowed by stronger characters. Do the math. Just to be provocative, maybe due to a Timey Wimey Ball of some sort they are the same person and Yuki/Elwood is using his godly powers to travel bewteen realities. Why not?
It wasn't Yuno's first time.She was lying, Yuno had actually been joined with Yuki during the first time line.
The third-world Reisuke Houjou grows up to be Sumio HaibaFuture-telling diary? Check. Pathetic doodles of said future? Check. Our resident psychopathic little boy grew up and dyed his hair green.
Is Deus an Eva?He looks like one.
Reisuke's puppets are representations of his parentsHe lost his parents, so, he decided to sew together two puppets that looked like his parents and make friends with them.
The Third became a serial killer because of YunoWhen Yuno accidentally hit The Third in the back with her makeshift spear in the omake, it caused something to snap inside of him and his repressed rage towards others spilled out and turned him into a serial killer.
The 9th has ancestral roots to Scottish demolition experts and French spiesAs if it wasn't obvious enough. On one hand, she's a Mad Bomber who is very efficient with explosives. Even with just one eye. She's basically a purple-haired Japanese cyclops. Only traits she doesn't have are being a drunkard and she lost her eye not because of explosive accidents, but because Yuki took that good eye out with a dart. On the other hand, she is quite the sophisticated Master of Disguise. She is able to easily take up the identity of someone she recently killed, like that rookie cop. Kinda sounds like a Spy with the 'Your Eternal Reward' knife. Traits she doesn't have include not being a smoker, not being a Knife Nut (that title goes to Yuno) may or may not be fluent in foreign languages and sleeping with one's parent (since she's a woman, that would be your father!).
Mirai Nikki is TTGL in the distant futureSimon become Deus Ex Machina: he is voiced by Norio Wakamoto and besides Pure Awesomeness provided with it, what do you think he did?. First opening has word "Rasen" ("Spiral") in its lyrics, implying that The Universe is overflowed with the Spiral energy and slowly collapses (after Deus dies, world began to absorbed by The Spheres of Destruction, which most likely are flows of the Spiral energy). The remaining part of Deus is actually the Core Drill. Of course SANITY IS FOR THE WEAK in this crazy world, so Yuno win the first contest because laws of logics and common sense means nothing to her.
Deus Ex Machina isn't the first God.Considering how succession is possible... There were others before him, they just picked some other method of succession. And considering how Murumuru works for whoever is God at the time, maybe she was created by the first God in order to help out, and just continues working for the next in line.
Yuki didn't really spend 10,000 years sulking over Yuno's death-[WARNING: this is a spoiler, if you haven't seen the end, don't read]- I have no doubt in my mind Yukiteru spend a long time in the void that the 2nd world became, but I don't think it was 10,000. The reason? We see his hair's grown significantly since Yuno committed suicide, but if he'd really been sulking that long, his hair would have been long enough to make MurMur a friggin wardrobe! That is, assuming she didn't occasionally cut his hair for him intermittently.
Gods in this 'verse can manipulate peoples' memoriesThe best example that comes to mind is how Yuno made several "memory edits" on herself, from the first and second world. A less noticed example would be Deus ex Machina himself, specifically manipulating Yuki's memories in order to make him believe Deus was an idea Yuki himself invented. Basically, Deus lives in Yuki's mind, but distorted Yuki's memory so that he'd think he made him up as an imaginary friend.
The 12th's hypnotism was granted as a bonus along with his diary.Perhaps Deus felt it was a little unfair for 12th to have such a limited diary. So, he gave him hypnotism as an added bonus, to try and even the field.