* AmericansHateTingle: The series is very popular in Japan ([[CondemnedByHistory or was]]), but it is loathed by some in North America due to its [[BrotherSisterIncest very concept.]]
* AssPull: A lot see [[spoiler:[[DerailingLoveInterests Manami's sudden reveal]] as a BitchInSheepsClothing]] to be this.
* SugarWiki/AwesomeMusic: Even those who don't like the series admit that the OP "Irony", performed by [=ClariS=] (of ''[[Anime/PuellaMagiMadokaMagica Madoka Magica]]'' and ''[[Literature/{{Bakemonogatari}} Monogatari]]'' fame) is pretty catchy.
* CondemnedByHistory: ''Oreimo'' was a phenomenon in the late [=2000s=] and early [=2010s=], as it was one of the first light novels to combine a HaremGenre story with [[OtakuSurrogate characters]] and [[MetaFiction stories]] that examined otaku culture. Fans loved being able to read about characters that shared their own interests, and the anime adaptation exposed the source material to an even bigger number of fans. However, several key issues began to propagate through the story that would ultimately lead to its downfall. The slice of life and otaku-centric content was put on the back burner for intrusive harem tropes, the [[AdaptationalJerkass anime increasing Kirino's bad behavior]] while still treating her as the primary love interest, and [[PutOnABus sidelining]] and {{derailing|LoveInterests}} fan-favorite characters. But what really sealed the novel's fate was the ending, which saw protagonist Kyousuke alienating all the other girls to turn IncestSubtext into outright text by hooking up with his own sister. The final nail in the coffin was the sheer amount of [[FollowTheLeader copycat]] light novels in the next few years that rehashed the BrotherSisterIncest plot of ''Oreimo'' to a shameless degree, along with degrading the observations of otaku media and culture into simply [[BetterThanABareBulb pointing out media clichés while still indulging in them]], seemingly for no other reason but [[PanderingToTheBase cheap and easy pandering]]. Even the original author of ''Oreimo'' would fall victim to the backlash years later, when his follow-up work ''Literature/EromangaSensei'' was adapted to anime and quickly panned; most reviews noted that ''Eromanga Sensei'' took all the flaws that had been present in ''Oreimo'' and [[FranchiseOriginalSin cranked them up to an intolerable degree]]. To this day, [[ItWasHisSled the first and only thing anime fans could tell you]] about ''Oreimo'' is that it's the show where the protagonist breaks up with his girlfriend to get with his sister.
* DieForOurShip: [[SatelliteLoveInterest A male side character introduced solely for the purpose of being a love interest]] is already bound to garner hate in a HaremGenre show, but actually start ''dating'' the ''main female protagonist'', and you're likely to find yourself staring down two barrels of fan hate, as [[spoiler:Mikagami]] found out, even after [[spoiler:it's revealed it was all an act by Kirino to make her brother jealous, and [[GayOption Mikagami ends up joining Kyousuke's harem]] after that]]. Surprisingly {{averted|Trope}} when [[spoiler:Kuroneko confesses to Kyousuke, and they end up going out]], but [[FanPreferredCouple she was already the most popular choice]] before that, and [[spoiler:they don't end up together in the end]].
* EnsembleDarkhorse: Can you guess? Gee, it's obviously the FieryRedhead OlderThanSheLooks Kanako.
* FanNickname:
** "Brousuke". With good reason, too.
** "Moenami"
** Fan Translators have nicknamed the manga "Delicious Thighs".
** The series' name has been shortened to ''Literature/{{Oreimo}}''. As this link would indicate, [[Website/TVTropes the tropers]] have noticed.
** The denizens of Japan's Website/{{Pixiv}} art site dubbed Kuroneko's little sister Tamaki "Kurokoneko", "Koneko" being "Kitten" in Japanese.
* FanonDiscontinuity: The parts of the ending where [[spoiler:Kyousuke alienates several of the girls]] and anything directly ''after'' [[spoiler:his wedding kiss with Kirino]] didn't happen. Nope, they totally got a HappyEnding. However, there are probably going to be some EpilepticTrees with [[spoiler:TheCameo in ''Literature/EromangaSensei'', such as taking place after the series and implying that some girls like Kuroneko and Saori might not have been alienated enough if they're still spending time with Kyousuke and Kirino]]. Which could count as HeartwarmingInHindsight if this were the case.
* HarsherInHindsight: There's at least one doujinshi[[note]]i.e., a fanmade comic book[[/note]] that has [[spoiler:Manami revealed to be a BitchInSheepsClothing]].
* HilariousInHindsight:
** The in-universe mahou shoujo anime "Stardust Witch Meruru" is stated to be intended for girls between five and ten, but its predominant fanbase is made up of males in their twenties.
** This is actually based on a few existing mahou shoujo shows, especially ''Anime/PrettyCure'' which markets half to little girls and half to adult males, and ''Franchise/LyricalNanoha'' which markets exclusively to adult males.
** Two years later, ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' was released.
** The PSP visual novel has Kirino as a playable route, using a NotBloodSiblings reveal. [[spoiler:Shouldn't have bothered...]]
** At several points, Kirino and Kyousuke's parents are portrayed as in the wrong or overreacting when they assume on evidence that the protagonist is having sexual thoughts about his own sister. [[spoiler:Whelp.]]
* LesYay:
%%** Ayase towards Kirino. (Administrivia/ZeroContextExample)
** Kirino's love for {{Little Sister Heroine}}s.
** Kirino is {{Tsundere}} towards Kuroneko even more than her brother.
* MemeticLoser: Kuroneko [[spoiler:after Kyousuke chooses Kirino in the end]], which also makes the fans put her on the "Black-Haired Girls Always Lose" list.
* MemeticMutation:
** My (Noun) Can't Be This (Adjective), which was a meme even before the anime. Tons of fanart used the phrase to comment on everything from other anime to [[https://danbooru.donmai.us/posts/792760 architecture]].
** [[MaleGaze Kirino's ass]], from an early scene where Kirino is browsing under Kyousuke's bed and she is shaking her posterior in the air as the camera focuses on it. Repeated a few more times later.
** Because of the novel's [[spoiler:ending, Kirino's victory]] started a "Blonde-Haired Girls Always Win" list.
* {{Moe}}:
** Actually a ''plot point'', since it's what turned Kirino into an unlikely fan of [[HGame H-Games]].
--->'''Kirino:''' [Little sisters] look so pure, you just want to protect them, or hold them tight!
** Kirino's [[{{Tsundere}} deredere moments]] are often quite adorable, especially in the manga. Of course, all the girls have their moments.
* NarmCharm: Who could forget this gem:
-->'''Kyousuke:''' [[LargeHam EROGE IS]] [[Anime/TengenToppaGurrenLagann MY SOUL!]]
* NeverLiveItDown: Anything involving a BrotherSisterIncest story is bound to suffer from this, ''especially'' among Western audiences. [[spoiler:Not least because it ends with ''canonical blood-related incest'' as the winning relationship.]]
* NightmareFuel:
** [[spoiler:Ayase!]] Don't mess with [[spoiler:her]] unless you ''want'' to trigger [[spoiler:her {{Yandere}} mode]]. It's worse in the PSP VisualNovel. [[spoiler:Her Bad Ending consists of her stabbing Kyousuke to death. Her NightmareFace and MadnessMantra before that don't help.]] Sweet dreams.
** [[spoiler:Kirino]] manages to outdo even Ayase in an [[WhatIf If route]] of the same VisualNovel, being [[spoiler:turned into a yandere GreenEyedMonster by a wish Akagi made concerning little sisters, with Kyousuke implied to have been crippled or killed by her to keep anyone else from seeing her precious Onii-chan]].
* OnceOriginalNowCommon: Once, the books were some of the most popular light novels in Japan, beating out even ''Literature/HaruhiSuzumiya'' (albeit in the twilight of the latter's popularity) and the ''[[Literature/{{Bakemonogatari}} Monogatari]]'' series. However, the ending started a chain of events that led to the series taking a massive nosedive. After the disappointment of the ending, many former fans of the series changed to indifference, and some outright bashed the series and exposed more and more of its flaws. [[CondemnedByHistory Today, the series is blamed for two trends in light novels very much maligned by the anime community itself]]: the usage of [[PanderingToTheBase otaku life-centric stories]] with [[BetterThanABareBulb so-called "meta commentary"]] on the genres and cliches endemic to the genre, and the growing trend of BrotherSisterIncest as a main or side romantic plot (a RunningGag among the anime community states that a poorly written harem light novel will always have the protagonist's little sister as one of the love interests).
* TheScrappy:
** Despite being the title character, a number of fans are put off by Kirino's initially {{Jerkass}} behavior and her poor treatment of Kyousuke, who is practically throwing away any chance to be seen as normal for her sake. This reaction tends to [[BaseBreakingCharacter vary between fans coming from the anime]], where her tsuntsun bad behavior is kicked up to eleven; the LightNovel source, which is more [[RescuedFromTheScrappyHeap evenly balanced]]; and the manga, where her words and mannerisms are much more deredere in response to Kyousuke's actions. This is actually intentional, as even characters in the novel think the same thing, but tend to see the glass half full and that Kirino is, while annoying, still important to them.
** [[spoiler:Ayase's extremely judgmental nature of Kirino's hobby has earned her numerous haters even among those who ''also'' consider Kirino a Scrappy.]] Like Kirino, [[RescuedFromTheScrappyHeap she grows out of this]], and her scary moments, when they show up, are always played for laughs or [[SugarWiki/HeartwarmingMoments d'awws]] after the initial conflict is resolved.
** Manami has managed to become one of the most hated characters thanks to the events of volume 11, [[spoiler:where it's revealed that she is the cause of Kyousuke becoming the useless guy that he is today and the catalyst behind the strain in his and Kirino's relationship. Her fistfight with Kirino at the end certainly doesn't help matters.]]
* SecondSeasonDownfall: ''Oh dear.'' The SliceOfLife and [[HaremGenre harem comedy]] was what fans came to ''Oreimo'' for, and {{Otaku}} viewers [[OtakuSurrogate having a lot of fun characters they could relate to]] brought in a ton of good press, turning the series into a phenomenon in its heyday. But as the story proceeded, the various otaku tropes gradually fell out of the story and became the target of cheap comedy, and the story either dropped characters OutOfFocus or outright began DerailingLoveInterests to laser-focus on the positives and negatives of Kyousuke's and Kirino's relationship -- the very things viewers ''didn't'' want to see from the series. By the time ''Oreimo'' was concluding, it was less of a comedic romp and more like a DeconstructiveParody of itself, and it ultimately [[CondemnedByHistory never got back out of that rut]].
* ShipToShipCombat: One is for BrotherSisterIncest, the other is against. Within the latter group, there are fans of Kyousuke x Manami (who consider her the most sane and normal of the choices) against fans of Kyousuke x Kuroneko/Ayase/other girls (who are seen as the more interesting choices).
* SoBadItsGood: The 3-part finale, [[spoiler:especially the final fight between Kirino and Manami]].
* StrawmanHasAPoint:
** The anime director from episode 8 is meant to be viewed as an ass for not adapting Kirino's light novel exactly the way she wants it (likely as a TakeThat, given that the scene is from an anime adapting a light novel), but anyone familiar with the way the anime industry works will know that catering to the whims of one fanatical otaku (who is stated to have quite bizarre tastes even by their standards) is a good way to lose money and possibly put a lot of people out of a job.
** [[spoiler:Manami Tamura]]'s outburst in the climax is meant to reveal her as a selfish BitchInSheepsClothing who believes she's {{entitled|ToHaveYou}} to Kyousuke's affection and wants to steal him from Kirino. The problem is that Kirino has been an outright {{Jerkass}} for the majority of the series, and [[spoiler:Manami]], being a close friend of Kyousuke for almost all his life, has been full witness to how poorly she treated her brother. It makes ''no sense'' that he would prefer someone who treated him like dirt for most of his life instead of someone who seemed to legitimately care for him, like [[spoiler:Manami]] did. And while the series attempts to portray her actions in the past as being the reason the Kosaka siblings turned out this way, her motivation to try to keep Kirino and Kyousuke apart as children [[WellIntentionedExtremist is very reasonable]] -- BrotherSisterIncest is considered taboo for awfully good reasons, and she didn't have any idea that they would turn out as screwed up as they did. Maybe Kyousuke never really did love her as more than a friend, but for him to reject her in favor of someone who was the definition of UngratefulBitch for so many years, and still is somewhat, is just baffling, and since she was a full witness to how badly Kirino treated her brother, it is hard to blame her for blowing up at them.
* TheyWastedAPerfectlyGoodPlot:
** In the series, Kyousuke eventually moves out temporarily for his studies. This is a monumental occasion for most young men, regardless of circumstance, and in most cases comes with a great amount of drama in real life, let alone television. The anime skips over the entire moving out process and goes from him being kicked out to him living alone in his small flat.
** In the same episode that happens, Kanako mentions in a throw-away line that her home situation was so bad that she ran away to live with her sister and is now trying to find a way to make up with them. Again, this has no build-up or acknowledgement within the episode at all.
** Season 2 wastes Season 1's plot. The first season's focus was on acceptance, and was quirky, fun, comedic, and charming. The second season veers the focus to a much more romance-centered plot, drifting away from dealing with the life of an otaku to finding out which girl is more in love with Kyousuke. What a waste.
* ValuesDissonance:
** To a lot of Western viewers, Kirino and Kyousuke's dad could be considered abusive. In addition to being cold to his children, at one point [[spoiler:he [[KickTheDog punches Kyousuke in the face hard enough to knock him down]]]]. That said, in defence of the father, the way Kyousuke [[TakingTheHeat takes the heat]] (saying he has been playing [[IncestSubtext siscon]] H-games on Kirino's computer) smacks of Kyousuke having [[BrotherSisterIncest sexual fantasies towards his sister]]. In addition, it's hard to say such a reaction was unprovoked, as Kyousuke threatens to punch his father for judging Kirino and even grabs him by the collar, clearly trying to get a rise out of him. To his credit, his dad also accepts Kyosuke's impassioned defense of the hobby immediately after. So in essence, the message is, "This is for violating my rules and daring to have an opinion. Now do whatever it was that made you feel good and what you think is right in a responsible manner."
** Kyousuke's mother has a fairly hands-off approach to child-rearing, although this isn't nearly as controversial. She only steps in when [[spoiler:she mistakes the fake-dating ploy for an incestuous relationship]].
** At a later point in the series, Kyousuke's parents actually kick him out of the house to make him study (and Kyousuke wasn't a particularly bad student), not letting him back until he finishes his preparatory exams. No-one has any problems with this. His mom has the added justification of suspecting him and his sister of [[BrotherSisterIncest getting along a little too well]], but that may very well be an excuse.
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