* AmericansHateTingle: Longchamp Naito is near-universally despised by a large percentage of overseas fans, due largely to his goofy appearance and rambunctious personality. He doesn't get nearly as much hate by the Japanese fandom, and even has a small following who lament the fact that he was removed from the anime due to his unpopularity.
* AngstWhatAngst: Lampshaded and subverted; in the Future Arc Dino notes that Yamamoto seems awfully chipper for having just suffered a great defeat (alongside being stuck in a future where his father's been murdered). It's partly a facade and Yamamoto later admits to Squalo in private that it's been eating at him.
* AntiClimaxBoss:
** Byakuran, despite all the build-up, [[spoiler: especially being a MultiversalConqueror of '''almost every universe in existence except the one Tsuna lives in''' and having all the knowledge and strength of those worlds,]] gets defeated swiftly in six chapters that reeks heavily of DeusExMachina.
** The Real Six Funeral Wreaths don't fare any better, considering they were either [[DroppedABridgeOnHim disposed of unceremoniously]] or had a DeusExMachina defeat them.
** Nearly all fights from the Curse of the Rainbow feel anti-climatic. Whenever somebody is taking the upper hand, the fight is briefly stopped or simply cancelled.
** [[spoiler: Bermuda, despite being a Cursed Arcobaleno and one of the strongest villains in the entire series, goes down by Tsuna's new SuperMode in one chapter. Immediately after this, Checker Face reveals himself to be a WellIntentionedExtremist and gives in to Tsuna's peace negotiations.]]
* ArcFatigue: The Future arc which, at the time of its completion, made up over half of the manga. Was even longer in the anime due to two additional {{filler arc}}s in the middle.
* BadassDecay:
** The only way to explain what happened to Adelheid Suzuki: she went from fighting evenly with Hibari to not being able to land a single blow on him within slightly more than a week. This is especially egregious when you consider that not only did she get a massive power boost from the "Vongola Sin", it was expressly stated that this power would continue to grow over the course of the next seven days.
** Tsuna goes through this in every single arc. He manages to defeat the BigBad from each arc, but in the next one is curbstomped by the first enemy he faces and ends up feeling completely insecure about it.
* BaseBreaker:
** Hibari: Half of the fandom loves him because of his MemeticBadass anti-hero status; the other half hates him, seeing him as a CreatorsPet JerkSue. It doesn't help that we see the other characters have to endure TrainingFromHell multiple times, something that Hibari himself never has to do, and every fight he participates in is [[AntiClimax anticlimactic]].
** Tsuna: Many see his reluctance to fight as a nice change from the cliche action hero. However, many other fans are annoyed that he's still a whiny idiot who keeps losing at the beginning of each arc.
** Iemitsu, Tsuna's father, often comes under criticism for his negligence towards Tsuna and Nana [[spoiler:(especially so in the final arc, where he nearly kills Tsuna during a poorly-communicated StealthMentor moment)]]. Others feel that the fact he's often protecting his family while working for CEDEF justifies the neglect.
* CargoShip[=/=]CrackPairing:
** Yamamoto[=x=]Wall was a common joke during the early days of the fandom, and is still remembered rather fondly. [[labelnote:explanation]]In his fight with Genkishi, Yamamoto has the upper hand right up until Genkishi tricks him into running headfirst into a reinforced steel wall, effectively OHKO'ing him. For some the scene was so jarring that it was [[{{Narm}} hilarious]], and thus the joke ship took off.[[/labelnote]]
** Hibari[=x=]Namimori. That is, shipping Hibari with the actual school building.
* CompleteMonster:
** [[MultiversalConqueror Byakuran]] is the Boss of the Gesso Famiglia and the BigBad of the Future Arc. Using his ability to communicate with and gain knowledge from every other Byakuran in a different parallel universe, he conquers each and every one of them until the only one left was the main universe. He planned to cement his grip on all reality by obtaining the [[AmplifierArtifact Tri-ni-set]]; first ordering the slaughter of the Vongola family itself and their friends and families, then releasing Non Tri-ni-set radiation into the atmosphere in order to kill all Arcobaleno members. While he displays a [[FauxAffablyEvil cheerful disposition]] around his subordinates, it's only if they hold his interest. In reality, he's ruthless and cruel. Once he "gets bored" of someone, he won't hesitate to have them killed. [[ItsAllAboutMe He will do anything to achieve his goal]], not caring if it would mean sacrificing innocent people or destroying the world and even referring to them as his toys.
** Daemon Spade, the main antagonist of the Inheritance Ceremony arc. To wit: [[spoiler: started a war lasting centuries between the Vongola and Simon (who had previously been brothers-in-arms who would rush to each others aid) in order to create his own ruthless version of the Mafia- because of this the Simon's history is lost and they're constantly abused by other families, with the current Simon Family being a group of teenagers who all lost their relatives due to persecution; gleefully murdered a young girl and her parents, and manipulated her grieving brother into thinking it was the fault of an innocent family (said brother was Enma, the current leader of the Simon Family, all of whom tried to fight the current Vongola Family to the death due to Daemon's involvement in the past); kidnapped, brainwashed, and tortured 13-year-old Chrome simply to push another character's BerserkButton; and even when on the brink of death had no regret for his actions and still believed himself to be in the right, calling Tsuna and the current Vongola 'weak'. Yamamoto, resident [[ThePollyanna pollyanna]] who forgives all of his enemies and never deals a killing blow, is ''furious'' with how Daemon screwed over the Simon and has no reservations about 'cutting him down'.]]
* DracoInLeatherPants: Almost every single villain in the series has received this treatment; they can do anything from [[WouldHurtAChild murdering children]] to enacting mass genocide by conquering the multiverse, and yet still be beloved by fans due to being attractive and[=/=]or charismatic.
* DudeNotFunny: 5-year-old Lambo might come across as annoying, but the comical physical abuse he receives from Reborn is just unwarranted and inappropriate to many.
* EarWorm: A good number of the anime's openings and endings, as well as some of the character songs can be guilty of becoming this.
* EnsembleDarkhorse:
** Squalo, the Varia's swordsman. Fans love his extremely [[LargeHam hammy]] bloodthirst (being a LongHairedPrettyBoy while doing it helps too), and in the popularity polls he's reached as high as 4th place.
** Fran. His unique, snarky, personality is loved by practically everyone.
** Enma. There's a reason he was the ''only'' member of the Simon Family that actually got a relevant role during the Curse of the Rainbow arc.
** Daniela, the 8th Boss of the Vongola Family. She only shows up in one chapter alongside the nine other bosses and doesn't say a word, yet ranked 6th and 10th in later popularity polls.
* EvilIsSexy: Boy is it ever in this series. As one fan made note, to be a villain in this series you must be ''fab''.
* ExpectationLowerer: First shown as being slightly weaker then Squalo, Basil is this for Tsuna, Yamamoto, and basically everyone else as the series progresses.
* {{Fanon}}:
** A generally accepted headcanon amongst the fandom is that Yamamoto's mother is deceased (given that she's never seen or mentioned despite Yamamoto's close relationship with his father). Likewise, it's often inferred that Hibari's parents are absent, or simply negligent.
** Kaoru is the only member of the Simon family not to have revealed his Earth Flame. People have thus theorized it to be either Ocean or Meadow, given that each Simon member has had the kanji for their Flame name in their actual name.
* FashionVictimVillain: Daemon Spade. For the most part the EvilIsSexy trope is in effect... and then he went and [[spoiler: possessed Mukuro. Now we have ''[[http://www.imagebam.com/image/a0fcae131803947 this]]''.]] Standard fandom response is laughing your ass off.
* FoeYay: [[FoeYay/KatekyoHitmanReborn Now with its very own page!]]
* GrowingTheBeard: By the Varia arc; the Kokuyo arc was the first to be DarkerAndEdgier, but the Varia arc did wonders in world-building and generally having a more engaging plot.
* HarsherInHindsight: Reborn's early interactions with Lambo. Sure, we know how [[SpoiledBrat annoying]] Lambo is about the "rivalry" thing and that he's not gonna be killed even by grenades, but once you realize it's an [[spoiler: adult hitman]] beating the living crap out of 5-year old kid... DudeNotFunny
* HoYay: [[HoYay/KatekyoHitmanReborn Has its own page.]]
* IKnewIt:
** What the entire fanbase was thinking when [[spoiler: the Simon Family was revealed to be Big Bad of the Inheritance Ceremony arc. People predicted that the Simon would have Earth-based flames, too.]]
** People who had read the manga predicted Daemon Spade's role as the BigBad in the anime's Inheritance Trials arc.
** [[spoiler:Hibari]] is the one who represented Fon in the Representative Battle.
** Almost everyone was betting on [[spoiler: Uncle Kawahira coming back to be revealed as Checker Face.]]
* IdiosyncraticShipNaming: The characters' {{Goroawase Number}}s often get used as ship names, leading to such things as 5927 (Goku/Tsuna). Even if you do know the fandom it's sometimes a bit tricky to work out.
* LauncherOfAThousandShips:
** Tsuna. Shipped with his {{Bishonen}} Guardians, almost every girl his age, his allies, [[FoeYay his enemies]], the list goes on.
** Chrome, by virtue of being the [[SmurfettePrinciple only female]] amongst the guardians.
* ItGetsBetter: Around volume eight. [[WhamEpisode Chapter 62]] to be exact.
* MagnificentBastard:
** Byakuran definitely fits the bill. [[spoiler: In every single one of the multiverses.]]
** With the reveal of who really masterminded the time travel plot, [[spoiler: TYL!Tsuna gets props for putting the kids in significant danger just to motivate his younger self. His own younger self can't believe it was really him.]]
** [[spoiler: [[BigBad Daemon Spade managed to successfully pull a GrandTheftMe on [[ManipulativeBastard Mukuro]]. Lemme just repeat that: '''He pulled a GrandTheftMe on ''Mukuro''.''']]
* MemeticMolester: Hoo boy, this series has a decent number of them.
** Mukuro Rokudo's gonna have some ''goddamn'' fun with you. And [[GrandTheftMe wants your body.]]
** [[SlasherSmile Birds]]... just [[GigglingVillain Birds.]] [[SarcasmMode Gotta love]] the creepy old sadists...
** DepravedHomosexual Lussuria of the Varia. Who during his fight with Ryohei expresses blatant [[FoeYay interest]] in him while simultaneously reveling himself to be a necrophiliac.
** Glo Xinia. It is heavily implied during his encounter with Chrome that if Mukuro hadn't stepped in when he did, Glo probably would have tried to rape her.
** Spanner's wildly regarded as a pedophile due to his interactions with Tsuna, which included stripping him for no real reason and handcuffing him to his bed. His blushing face (in regards to the X-Burner technically) and sudden HeelFaceTurn don't help.
** [[EvilOverlord Byakuran]] smiles constantly, loves "symbolic flowers", kills off one of KHR's other memetic rapists, and has signature moves where he 'penetrates you'. Oh and let's not forget his image song where he asks you to 'give him your body'. Then there's his blatant obsession with Yuni once she escapes from his grasp. Although there is a good reason for it, the vibes are still there. Not to mention his grabbing of Tsuna from behind and whispering into his ear...
** Julie Katou wants you to know that you have "date plans" with him. And he will help you dress for them~ [[spoiler: Though it is all due to Daemon Spade possessing him]].
** Daemon Spade's a pedophile that wants your body. ''Nufufu~'' [[spoiler:How ironic that one of the {{Memetic Molester}}s above is a [[GrandTheftMe victim]] for this guy.]]
* {{Moe}}: A lot of the girls can qualify, but especially wide-eyed ShrinkingViolet Chrome. Tsuna is a male example.
* MoralEventHorizon: [[spoiler:Mukuro's utter and rather brutal LackOfEmpathy when fighting with illusions of the Kokuyo Gang raised a few eyebrows among fans, considering they're the main source of his PetTheDog moments.]]
* {{Narm}}:
** Despite the clear amount of drama and "OhCrap" moments going on in the Inheritance Ceremony arc, the fandom still laughed its collective ass off at [[spoiler: how Daemon looks in Mukuro's [[http://www.imagebam.com/image/a0fcae131803947 body]].]]
** [[http://www.mangahere.com/manga/katekyo_hitman_reborn/v26/c240/6.html Giant Byakuran head in the sky.]]
** [[CreepyTwins The Bloody Twins]], who were horrifying in the manga, look more like two stoned freaks in the [[{{Bowdlerize}} anime]].
** [[spoiler: Bermuda's [[http://c.mfcdn.net/store/manga/880/TBD-401.0/compressed/v020.jpg adult form]]. It's hard to take it seriously. And his "[[http://c.mfcdn.net/store/manga/880/TBD-403.0/compressed/o018.jpg 100% Lethal Final Technique]]" [[DoesThisRemindYouOfAnything Do these shapes remind you of anything?]]]]
* PeripheryDemographic: Did the number of [[{{Bishonen}} bishies]] in the story really convince you that this series was ''just'' for guys?
* TheScrappy:
** 5-year-old Lambo. Most of the fans find his BrattyHalfPint tendencies annoying rather than endearing.
** M.M. isn't very liked at all, due to her bratty personality and the horrible way she acts towards Chrome (though [[DoubleStandard for some reason]] her treatment of Chrome is given much more hate than Ken's equally bad treatment of her).
* ShockingSwerve: The real identity of Checker Face is [[spoiler: Kawahira, the Ramen shop owner...[[ChuckCunninghamSyndrome who is that again?]] Not only that, but he and Yuni's ancestor are secretly from an ancient immortal species that have existed on Earth since before humans!]]
* {{Squick}}: Gamma admits to having an unrequited love towards his boss Aria, and when she passes away he says he feels the same way about her daughter Yuni (which Yuni appears to reciprocate). The problem is that Gamma is in his thirties while Yuni is fourteen or younger.
* TheyWastedAPerfectlyGoodCharacter:
** There were many who were DemotedToExtra in the final arc, such as Ryohei, Lambo, and even Yamamoto and Gokudera. Especially jarring since they had just received brand new Cambio Forma weaponry in the previous arc, which Gokudera and Yamamoto had barely shown off.
** 20YL!Lambo, the [[CharacterDevelopment mature]], [[{{Hunk}} handsome]], and incredibly BadAss future version of 5-year-old Lambo, only ever appears in one chapter. It's justified that he can't show up in the Future Arc due to Lambo not being in possession of his 10-Year Bazooka, but even afterwards it's only 10YL!Lambo that makes a reappearance.
* TheyWastedAPerfectlyGoodPlot:
** The Arcobaleno Arc could've been great, if it wasn't for its premature ending.
** Mukuro and Hibari never got their rematch despite the build up. They ''do'' get to fight again in one of the anime's filler arcs, but it's cut short by Tsuna's intervention.
* UncannyValley: [[spoiler: Bermuda's true form resembles a doll whose proportions are too unbalanced. His eyes are too large for his baby like face, has a nose that is practically nonexistent and has the arms of a bodybuilder attached to an adolescent body.]]
* ViewerGenderConfusion:
** Mammon's gender is often debated between fans. Due to being a baby wearing an [[InTheHood eye-concealing hood]] their features and voice are both gender-neutral (as are the pronouns used to refer to them). Viz Media refers to them as male in english translations, and they're grouped into the male character category in the third popularity poll.
** Kangaryu, Ryohei's box weapon, is female. Isn't helped at all by the fact that some people translate her name as ''Man''garyu.
* {{Wangst}}: A strange example. Tsuna's life is supposed to have gotten better after meeting Reborn, but Byakuran tortures him by saying how much his life sucked during the Future Arc. Ironically, he is kind of right considering how at the beginning Tsuna was exasperated with the idea of not going home while his friends were trying to stay calm about it.
* TheWoobie:
** Gokudera, especially when you learn about his past.
** Chrome, due to the hell she goes through. Her parents abandoned her to die, half her organs are missing, she's homeless and more often than not starving, she's constantly belittled, and in the Inheritance Ceremony arc [[spoiler: she's [[HypnotizethePrincess hypnotized]] and tortured by D.Spade purely to push Mukuro's BerserkButton.]]
** [[spoiler: 20YL!Lambo, particularly when you realize, thanks to Byakuran, exactly what kind of [[BadFuture future]] he has to return to.]]
** Yuni, and by extension Luche and Aria. Luche was BlessedWithSuck, received the less-than-beneficial end of the CursedWithAwesome stick shared by her other partners, and worse yet has to pass that on to all her future descendents. [[spoiler: Yuni has to sacrifice herself in the Future Arc to restore the Arcobaleno and in turn defeat Byakuran, but she's terrified of death and can't go through with it until Gamma joins her and they die together. The scene is regarded as one of the most [[TearJerker tear-jerking]] of the manga/anime.]]
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