* [[BannedInChina Banned In New Zealand]]: According to {{the other Wiki}}, the anime adaptation was refused classification in New Zealand, on the count that it "promotes child pornography"[[note]]Which becomes HarsherInHindsight if you take note what happened to [[Creator/ScottFreeman Issei's former dub VA.]][[/note]]. On the other hand, all three of the dubbed seasons are completely available in Australia. All three seasons have been recently banned in China as well.
* {{Expy}}: Issei's design is actually based on [[Anime/SCRYed Kazuma]] because the author is a fan of the series.
* FlashbackWithTheOtherDarrin: For the dub, when they go back to moments of the first two seasons where Issei talks, this happens of course. In the case of his gate-crashing Riser's party, they even put in a new line to go with the new voice actor.
* FanNickname:
** Hypnobutt - Koneko [[MaleGaze swaying her butt on the screen in the ending]]
** Weapon [[{{Netorare}} NTR]] - [[spoiler: for Issei and Kiba ''hijacking'' both True Longinus and ''all'' of Siegfried's swords respectively.]]
** GAR-sper - In some circles, Gasper after his awesome moment in Volume 10.
** [[Manga/{{Bleach}} Kenpachi dragon]] - Grendel is called this in the {{Imageboard}}s thanks to his BloodKnight attitude while fighting Issei.
** Dragon swag - What fans refer to when Issei attracts someone's attention.
** Dickora - for Diodora, which further cements his status as TheScrappy.
* IKnewIt: Some people got it correct when [[spoiler:they thought that Great Red was going to help out both Issei and Ophis. ''No one'', however, thought that Great Red has a {{Delinquent}} personality.]]
* NamesTheSame: Sister Creator/AsiaArgento
* RelationshipVoiceActor:
** Although it was a short-lived one, Creator/ShizukaIto and Creator/HitomiNabatame reunite here as Akeno and Raynare.
** Creator/ScottFreeman and Creator/JamieMarchi played another OfficialCouple in ''LightNovel/BakaAndTestSummonTheBeasts'' (Yuuji and Shouko).
** The 2nd season of the anime reunites [[AyaneSakura Akane Isshiki]], [[Creator/MaayaUchida Rei Kuroki]] and [[HarukaYamazaki Mizuha Amagi]] from [[Anime/VividredOperation Vividred Operation]] but ironically their characters will never get to interact with each other in the anime.
** Also in the 2nd season of the anime, [[Creator/YokoHikasa Emilia Justine]] [[LightNovel/TheDevilIsAPartTimer and]] [[Creator/RyotaOhsaka Satan Jacob]] are reunited but at least this time, Emilia isn't out for Sadao's blood. But if Issei is hurt...
*** [[AzumiAsakura Emerlda]] was already there. [[Creator/HirokiYasumoto Albert]] pops up to but he's evil now.
*** Remember that [[BadassBystander awesome convenience store worker]] that threw paint balls at Emilia's attacker? He's [[Creator/YuuichiIguchi Saji]] over here.
** [[Creator/HirokiYasumoto Kokabiel]]: [[YuukiKaji Issei]], [[LukeIAmYourFather I am your father.]] [[Anime/AquarionEvol 12,000 years ago...]] And he's also [[VideoGame/AsurasWrath Asura]]. Though he got demoted from demi-god to fallen angel, no ''wonder'' the Gremory team couldn't even scratch him.
** [[Creator/YuukiKaji Issei]] and [[Creator/YuuichiNakamura Sairaorg]] have ''a lot'' in their list. [[Manga/DontenNiWarau Fortunately,]] [[VideoGame/FinalFantasyXIII they're]] [[Anime/GuiltyCrown allies]] [[Anime/AquarionEVOL this]] [[Anime/{{Durarara}} time]] [[Anime/FairyTail instead]] [[Anime/NobunagaTheFool of]] [[Anime/NobunagaConcerto enemies.]]
** For the dub, [[Anime/PantyAndStockingWithGarterbelt the Anarchy Sisters]] reunite in the third season as [[Creator/JamieMarchi daughter (Rias/Panty)]] and [[Creator/MonicaRial mother (Venelana/Stocking)]].
* PlayingAgainstType:
** In the dub, the cultured and flirty Devil Rias Gremory is voiced by the [[{{Lust}} slutty]] and [[SirSwearsALot foul mouthed]] FallenAngel [[Anime/PantyAndStockingWithGarterbelt Panty Anarchy]].
** Again with the dub, the perverted nice guy Issei Hyoudou is voiced by [[WebComic/AxisPowersHetalia United Kingdom]], the [[MeanBrit fake]] [[QuintessentialBritishGentleman British gentleman]]. At least, for the first two seasons.
*** For the third season, Issei gets ''two'' Playing Against Types: [[Creator/JoshGrelle he is voiced by]] the fearful UnluckyEverydude [[Manga/FutureDiary Yukiteru Amano]], as well as [[LightNovel/InfiniteStratos Ichika Orimura]], the one guy in an all-girls academy who has an UnwantedHarem [[CluelessChickMagnet and is all the oblivious about it.]]
* SleeperHit: Of the {{Winter 2012 Anime}} season. Heck, no one expected that the series would even sell 10,000 DVD [=/=] Blu-ray copies in the first week!
* WhatCouldHaveBeen: Supposedly, one of Issei's power-ups was to ''suck Rias' breasts''. Unfortunately, that was already too much for Fujimi Shobo, so the author resorted to something else.
* TheOtherDarrin: For the third season's dub, Creator/JoshGrelle replaces Scott Freeman as Issei, and Kelly Angel replaces Teri Rogers as Akeno.
** The dub acknowledges this in a very ''Series/{{Roseanne}}'' like way in the second episode.
--> '''Venelana''': You sound so different, Akeno!
* TheWikiRule: [[http://highschooldxd.wikia.com/wiki/Main_Page Sure thing, dawg!]] '''WARNING:''' Gets a little NSFW in some places.