Note, there are some minor spoilers but it’s nothing that will affect your experience watching Mirai Nikki. I will (try to) only use minor spoilers for this review.
Based off the manga of the same name by Esuno Sakae, Mirai Nikki was one of the most popular anime airing during the fall season and continued having popularity into the winter season. Despite knowing it was popular I wasn't really expecting anything. What I got was one of the worst anime I’ve watched so far, one I would not recommend to any one and I will try my best to explain why.
Mirai Nikki starts off with showing an average day for the protagonist, Amano "Yuki" Yukiteru. He is a loner who spends his time writing diary entries on his cell phone about everything he observes. Having no real life friends, Yuki resorts to having imaginary friends instead, Deus ex Machina and Mur Mur. One day Deus gives Yuki a special cell phone. Since he thinks that Deus is just an imaginary friend, Yuki just shrugs it off for now. Little does Yuki know that his imaginary friend isn't as imaginary as he thought and soon discovers that Deus is the god of space and time as well as dying and in need of a successor. Yuki, along with 11 others, has been selected to be part of a battle royale where the participants have a diary with entries from the future, each with their own “powers.” The goal is to find and kill the other participants with these diaries within 90 days. The last one standing is rewarded by replacing the dying god and is supposed to use their powers to stop the world from ending. In order to survive, Yuki reluctantly teams up with another diary holder who just so happens to be his yandere stalker, Gasai Yuno.
Sounds interesting? Well, Mirai Nikki is interesting in some aspects, I’ll give it that, but it’s still far away from being good. The premise is indeed interesting but the premise alone does not make an anime good. There are several things that can make an anime good as well several things that can make one bad. Mirai Nikki decided go down the edgy and “mature” route and falls flat on it’s face but tries save face and impress the viewer with explosions, over the top action, violence, blood, gore, and “dark” stuff to try to trick the viewer into thinking that Mirai Nikki is a dark and mature anime because it doesn't hold anything back. Unfortunately this doesn't really work because of the ridiculous levels of edginess that the show provides. That is unless you’re just blind to the plot holes, aren't much of a thinker, have your brain turned off, and/or you just watch solely for entertainment that don’t really care about the finer details in anime. Even if you're one of those people you still might or might not like Mira Nikki.
Mirai Nikki starts off being an “enemy diary holder of the week/arc” type show with enemies ranging from 5 years olds and teenage cult leaders to dog trainers and terrorist. Mirai Nikki ends up having plot holes as it tries to mix in plot twists, shock value, and (poorly done) romance between characters in a rather forced and messy manner while it’s at it. Such plot holes include: a 5 year old getting poisonous gas (who the heck lets a 5 year old buy this, in fact, where did he get the money to buy it? How did he even get buy a mask gas small enough to fit a small child’s face), why Deus chose people who are somewhat insane to being extremely insane beyond belief to be candidates for being his successor with only a few “sane” people being selected (giving crazy people the chance to become god and rule the universe, absolutely genius), and where the heck did she pull that motorcycle out of (her ass? If you’ve seen Mirai Nikki already you should know what I’m talking about).
Shock value is a big one that Mirai Nikki likes to throw at you as it tries to be overly dark, out of nowhere, and extreme about several events and character backstories, such as being constantly gang raped by an entire cult or a terrorist blowing up a school room by room just to try to kill 2 people (and while I’m at it, why didn’t the terrorist blow up the entire school all at once or at least the entire building the 2 other diary holders were at to ensure the death of her targets instead going room by room? That just allows the targets to escape).
I won’t get much into plot twists since I only plan on using minor spoilers, just know that they aren’t good and maybe even make you cringe if you have your brain on and actively thinking. The same can be said for the ending, which I will just say is very bad and there is a reason why there is sequel OVA… which is even crappier than the anime.
The characters are a rather painful bunch to watch as well. Mirai Nikki tries very hard to make the cringe worthy and terrible romance between the two main characters, Yukiteru and Yuno, to be well written and beautiful. Their romance is one of the worst, if not the worst, I’ve seen out of any anime so far. Their romance is rather messy and the show tries to play it off as something beautiful, because locking someone up and keeping them in a weak psychological state is romantic and beautiful. Yukiteru and Yuno don’t really get much character development. Yukiteru always reverting back to his whiny Shinji archetype self, even when he does a 180 in character. Yuno never goes beyond being a stereotypical yandere with no substance. I will admit I haven't really seen that many yandere characters in anime but I'm pretty sure Aragaki Ayase is a better yandere than Yuno will ever be.
Yukiteru is whiny or the sake of being whiny and no reason to justify his whiny nature. He was raised into a rather normal family with parents that treat him well as well has having a normal background. Yes his parents did get divorced and that has been known to cause problems in some kids and yes being raised in a normal family doesn’t gratitude you won’t have some sort of problem or problems, but Yukiteru seems have been born whiny just to be a whiny protagonist with no other reason other than that.
Yuno’s insanity is also used to explain her actions, no matter how stupid or unbelievable they are, and apparently that means people can go “she’s crazy so she does crazy stuff and acts crazy and doesn’t follow sane trains of thought and stuff.” It still doesn’t change the fact that her insanity is way too over the top to take seriously. Depending on who you are, Yuno will either be the most likable character because of these reasons or the most unlikable character because of these reasons.
As for the rest of the characters, only Ninth and Akise Aru are worth mentioning as the other characters are pretty much there to either be an ally to Yukiteru or be enemies. They are handled poorly and don’t get developed. They only exist so that they can be as over the top, “unique,” and edgy as possible and/or so that there can be a “plot.” That’s really sad to say about a cast. Ninth and Akise are the only two that some major importance to the plot (for spoiler reasons) and are less unlikable as the rest of the cast. Ninth also does get romantically involved with another character but the romance is poorly done but it’s still better than the romance between Yukiteru and Yuno. Akise is also a Kaworu (Neon Genesis Evangelion) clone and has romantic feelings for Yukiteru for spoiler reasons.
Mirai Nikki was animated by Studio Asread, which really hasn't done anything that stands out aside from Mirai Nikki. The animation isn’t anything praiseworthy as well and there isn’t much to talk about. It’s average at best. The shading and lighting is very standard, nothing praiseworthy or bash worthy. Although Mirai Nikki tried so hard to be a dark show, the bright colors used only served to make Mirai Nikki fail ever harder. There isn’t any smooth or fluid movement and most of the movement was rather stiff and there are several still frames used. The CGI is rather awful, but CGI is usually used an awful way that is painfully obvious and distracting in many anime. The blood is also iffy and isn’t anything to look forward to if you’re a blood and gore fan. The animation is below average and there really isn’t anything to say good about it.
The soundtrack was just there and very forgettable. It really didn’t do anything other then just be in the background. As far as voice acting goes… I haven’t seen the dub but I have been told that the dialogue is rather messy and poorly translated and some mixed opinions about Brina Palencia as Yuno and the rest of the sub being below average to average at best. I can say for the sub that the voice acting wasn’t anything worth praise, it’s pretty standard and not really worth talking about with the exception of Murata Tomosa’s performance as Gasai Yuno. Her performance is hands down the best the show has to offer with the only downside is the annoying “YUKII!!!” you’ll hear her say (and something tells me the dub also suffers from this) and she really needs to do more characters. (I like Murata’s voice…) The first ending and the second opening aren’t anything good, the second ending is kind of nice but only the first opening is worth talking about. The first opening is rather good and the most (if not the only) enjoyable part of Mirai Nikki and the only thing Mirai Nikki has that is worth watching. There is also the third opening and ending but the third opening is an edgy mess that tries to show as much blood and gore as possible.
There isn't much to enjoy about Mirai Nikki unless you just decide to turn your brain off or one of those that just turn their brains on at all when watching anime, even then you still might not like it. It’s best to stay away from this anime if at all possible. It has mediocre animation, forgettable soundtrack, standard and not noteworthy voice acting (aside from Murata’s performance as Gasai Yuno), terrible and forgettable characters, and a ridiculous plot that tries so hard to be “dark” and “mature” only to miserably fail and be cringeworthy. Just stick to the first opening and nothing else.
This opening is the only thing worth watching from Mirai Nikki.