These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Awesome Art: The first few volumes have quite bad art. After that, it sort of evens out. But as of Season 2- just in time to benefit Cerebus Syndrome- every single page becomes absolutely beautiful- the poster art even more so.
Ass Pull: Part of the Gecko Ending of the second season anime. Tsukune somehow manages to call upon vampire powers he's only used once before, when he was injected with Moka's blood last season, with pretty much no foreshadowing. Whether or not you've read the manga, it just seems absurd.
Cliché Storm: The anime adaptation in comparison to the manga.
To be fair, the manga was also this...initially. Before Season 2.
Complete Monster: Gyokuro Shuzen is the Evil Matriarch of the Shuzen family and the leader of the genocidal anti-human organization Fairy Tale. In her position, Gyokuro tasks her men with sowing the seeds of the Human World's destruction, aiming at nothing less than humanity's annihilation by awakening the ancient vampire and Eldritch Abomination Alucard. Gyokuro also brainwashed her gentle, kind daughter Kahlua into being an efficient assassin that cannot refuse her orders to kill, viewing Kahlua as a proud achievement. When she confronts the heroes, Gyokuro rips off her stepdaughter Moka's Rosary Seal, and proceeds to cheerfully laugh, enjoying the pain it causes Moka. It is then revealed that Gyokuro had implanted bits of Alucard into the other Shuzen vampires, which have devoured them from the inside out and turned them into ravenous ghouls. When Moka begs on hands and knees for Gyokuro to save her beloved Tsukune from this fate, Gyokuro agrees...and then mocks Moka's weakness before punching her in the face. She even directs Kahlua to murder her beloved little sister Kokoa with no remorse, Kokoa being Gyokuro's own daughter as well. It's revealed Gyokuro's rage stems largely petty jealousy at Moka's mother, her rival Akasha. When she fuses with Alucard, Gyokuro gloats that she will destroy everything Akasha ever loved and destroy the world she protected. Beautiful, sadistic and unforgiving, Gyokuro viewed all in her path as nothing more than stepping stones for her own power.
Creepy Awesome: Part II turns Tsukune into this, especially towards the end. Also Kahlua, and ESPECIALLY Alucard.
Hitomi constantly rants about how beautiful Moka is, while trying to kill her or turn her to stone.
In the anime, Kurumu and Yukari's fights often devolve into mocking each others' breast sizes, and they aren't afraid to touch each other to make a point.
"Funny Aneurysm" Moment: The joke in chapter 1 season 2 where Mizore wants to have babies with Tsukune becomes a lot less funny in the Snow Fairy arc when we find out there was a reason for her wanting a baby with him.
Remember when the Security Committee under Kuyou interpreted Youkai's "no humans" rule as an instant death penalty, to be carried out at 4:00 following the discovery, of "filthy human spies"? Aside from the Harsher in Hindsight example below, when you learn in Season II during San's arc that killing humans is strictly forbidden to monsters on pain of death, you realize that Kuyou may have actually put the entire Security Committee at risk!
Course, it could just be that that rule only applies in the human world.
Germans Love David Hasselhoff: While far from obscure in Japan, it should be noted that in North America it consistently debuts in the top 5 on the New York Times Best Seller Manga list, sometimes even reaching #1.
Growing the Beard: The second season of the Manga (NOT the Anime) is universally regarded as a huge step up in quality from the first.
Harsher in Hindsight: That arc from the first serialization where the Newspaper Club and Student Police crossed swords at an even higher intensity than ever before, thus kicking off Cerebus Syndrome for the manga? Turns out it's Fairy Tale's fault.
All those Almost Kiss scenes from early in the manga and in the anime are likely this, now with chapter 66 in the second manga serialization with Outer Moka seemly being killed off, after she and Tsukune admit their feelings and have their first and maybe last real kiss, and dying afterwards in his arms.
Idiot Plot: Too often, Tsukune and/or his harem have a moment where they go off and do something plain dumb, only to get into loads of trouble. This is followed by an apology...until it happens again, in the next chapter. It seems to be fading as the story goes on, however. Mostly because trouble is followingthemnow.
Yukari is an 11-year-old witch. Nobody should look that cheery and adorable when threatening people with magical warfare. (The magic wand with the heart-shaped topper just makes it cuter.) And then there are the bits where she looks genuinely sad.
Hitomi Ishigami virtually blowing up the whole school with a magic mirror toward the end of the first serialization. She gets her comeuppance yet again when she's arrested for the crime. Her motive for doing this was a revenge scheme against the Newspaper Club for exposing her plot to turn the most beautiful female students into stone and use of modeling sessions as a pretense and getting her fired for it. So in other words, she wrecked Yokai Academy out of spite toward just a few of the students. It's also arguable that she may have crossed it earlier when she schemed with the Security Committee and Kuyou to murder Tsukune for the same reason.
Kuyou himself crosses it with his interpretation of the school rule "No humans allowed" as "Death to all filthy human spies!". Not only is he willing to commit murder based on his own twisted interpretation of a school rule, he's also completely willing to risk the lives of the existing members of the Security Committee by having Tsukune murdered. To make his mindset much worse, if Tsukune died and the Security Committee was eventually caught, Fairy Tail would've won.
Kanade Kamiya has a lot of potential crossing points, but it's most likely that he crossed it by killing Marin Kawamoto's husband in front of her.
Gyokuro Shuzen is a nasty one, and her sadistic treatment of Moka just a chapter before was bad, but when she, without a single ounce of hesitation or regret, orders Kahlua to kill her own beloved little sister Kokoa? And remember that Gyokuro is Kokoa's birth mother as well.
It's possible that Hokuto and Kiria may have crossed it during the festival arc. Hokuto chains up all of the harem (with the exception of Moka who had been kidnapped) inside a barrier created by Mikogami's rosary so that they don't stop him. Tsukune tries to fight him but he keeps getting knocked down and beaten to a bloody pulp RIGHT IN FRONT OF HIS FRIENDS. Kiria's was when he had Moka. He told her that he would let her go free if she removed her rosary by herself (back then only Tsukune could do that). To motivate her, he gave her a live camera feed on Hokuto beating up on Tsukune. Basically it boils down to, "Do the impossible bitch, or your boyfriend is gonna be paste."
Ultimately subverted with Lady Oyakata; she seems to have already crossed it by her own admission, but Ruby, her former disciple, refuses to believe it even after Oyakata critically wounds her during the boss fight and even saves Oyakata from certain death when her binding spell backfires on her. Oyakata repays the favor by using the last of her life force to sufficiently heal Ruby.
If, after all he had done and what was revealed about him, you still had a small shred of hope for Miyabi Fujisaki, that went out the window the moment he murdered Outer Moka in cold blood by destroying Moka's rosary.
Nagare Kano is already well past the MEH by the time he appears, but blackmailing a girl into bailing on the Newspaper Club for him when they're in a deadline? Putting the Newspaper Club's hard work at risk over your lust!? Calling this Kodak fiend a pervert at this point would be an insult to perverts everywhere.
Out of Focus: Hey, does anyone notice that Tsukune is missing in much of the official art and Capu2's intro?
Periphery Demographic: Perhaps owing to the increasingly bishonen male cast and school life elements, this series has a surprisingly faithful female fandom.
Seasonal Rot: The prevailing opinion is that Season 1 of the anime was okay, and Season 2 sucked. (This was not the case in the manga, in which Season 1 was okay- depending on what you read it for- and Season 2 was awesome.
They Changed It, Now It Sucks: The anime adaptation lacked much of the original manga's plot, character depth, and atmosphere, and unapologetically bombarded the viewers with panty shots at the most inappropriate moments (read: all the freaking time). The second season was an In Name Only adaptation, being completely original and almost indisputably inferior.
Values Dissonance: Kurumu's mother Ageha is a really sweet person, quite charming and supportive of her daughter* and her daughter's friends. Being a succubus, though, she can have a few little quirks that really embarrass poor Kurumu, such as flirting with Tsukune a little or offering to teach him how to be a better lover for Kurumu.
While viewing Moka's memories, Tsukune and the others are shocked and horrified that her father Issa ordered her and Akuha to fight to the death. Apparently, this is simply normal behavior for vampires.
The Woobie: All the girls have their own woobie moments, but the one that takes the cake would be Mizore. Spurned by her childhood love because she's not human; assaulted by the teacher she had a crush on, only to get the reputation of being violent from defending herself and became anti-social; forced into a loveless marriage because her race is unable to bear children when they're not young anymore, with her fiancÚ from an organization that would destroy her entire race if they don't agree; and to top it off, no matter how much she loves Tsukune, he will most likely never return her feelings.
She cements this position in the second manga after her near-rape by aforementioned fiance, attempted suicide because of it, Kurumu saving her and Mizore breaking down into hysterics in Kurumu's arms. The whole event showing that she has very, very deep emotions behind her kuudere exterior, and making anyone want to hug her and tell her "it's all ok" like Kurumu was able to.
She gets an in-universe woobie moment when, in the events leading up to the rape, she tries to seduce Tsukune into making love with her so she wouldn't be forced into an arranged marriage she doesn't want — he sees how scared she is about whatever is going to happen and tries to hold and comfort her, despite her being naked and lying on top of him.
Kurumu gets her own woobie story when she accidentally charms Tsukune but can't bring herself to un-charm him, just so she can know what it would be like if he wanted her. Even when charmed, she's unable get him to say to her a simple "I like you". She is - understandably - emotionally devastated.
Even more heart-wrenching is that this comes after the arc with Mizore. Kurumu puts up a front that she and Mizore are nothing but adversaries for Tsukune's love, but she unhesitatingly leaps out the window to save Mizore when she tries to kill herself. Kurumu has so much love in her heart for her friends, and she keeps it bottled up so it won't hurt her even more when it isn't returned.
Moka certainly qualifies. At the beginning of the manga we're told that Moka was picked on and ostracized by her peers and never had any real friends. Later on we find out that Moka's mother was eaten alive right in front of her. To make things worse, the rosario around her neck seals off her memories surrounding the event. What's left is a Moka who spent her childhood terrified of the gap in her memory and with no idea who she really is. Also, she doesn't know that her mother is dead, so she's left wondering why her mother disappeared.
Even worse, Omote Moka being a more-or-less golem created along with Ura's seal, means that Akasha never knew her to begin with. Meaning that Omote herself has never technically even had a mother, the woman she's searching for so desperately has never met her. Meanwhile Omote is left to face the realisation that she's a magical entity that has to possess Ura's body to have physical form. Oh and she's really only five years old.