* ActorAllusion: Newton Pittman previously played a character [[Anime/DarkerThanBlack who has no problems playing both sides if he has to survive.]]
* AuthorExistenceFailure: Bob Magruder, the English voice actor of Pope Matthai Reese, passed away on January 2, 2015 due to illness. This was one of his last roles alongside Freezing Vibration as Christopher Mably.
* DevelopmentGag: Ayu Mitsuari's character design was in fact based on a [[WhatCouldHaveBeen rejected concept art]] for Misaki. According to WordOfGod, such rejected designs would be locked away. But since Ayu's role would be of a girl who wanted to be Misaki but failed to do, using an old design for Misaki was fitting.
* FanNickname:
** While not calling her by her InSeriesNickname "Biri Biri", fans also call Mikoto pikachu-tan (pikachu-chan) or pika-pika-tan.
** Thanks to Mikoto in episode 10 of Railgun, fans have now call Touma's doctor, Dr Gekota! - ~ - (At least it beats calling him Frog Face but it still doesn't beats his title [[spoiler:[[AwesomeMcCoolname Heaven Canceller]]]].)
** Superman is what some fans are calling [[spoiler:Acqua of the Back]].
** Enter ''Tou'''MAN.'''''
** Cue '''The''' ''[[{{Tsundere}} Thundere]]''.
** '''''Pendex''''' for Index's Johann's Pen Mode.
** "Fre nda" for Frenda Seivelun, who had been killed by being sliced in half.
** "Walking Porn" for Oriana Thompson, who is practically MsFanservice incarnate.
** "[=HOThinus=]" for Othinus, when she was revealed to be incredibly attractive and wear a {{Stripperific}} outfit.
** "OTP" for Othinus Touma Pairing.
* NoExportForYou: The video games, trading card games, the manga adaptation of Miracle of Endymion and various audio dramas were not released overseas.
* PlayingAgainstType:
** Creator/BrynApprill as Awaki Musujime of [=GROUP=].
** Creator/AustinTindle as Accelerator.
** Both Akiko Hiramatsu and Kara Edwards for Vent/Vento of the Front.
* RealitySubtext: In the Index-tan special, someone who used a voice changer asked Kaori Kanzaki about her age, her Stripperific outfit, ''and'' her [[Creator/ShizukaIto voice actress']] LadyDrunk antics in the launch of the anime.
* RelationshipVoiceActor:
** Many voices from ShugoChara show up in this series: [[Creator/KanaeIto Saten as Amu]], [[Creator/AkiToyosaki Uiharu as Suu]], [[Creator/AtsushiAbe Touma as Kuukai]], [[Creator/KanaAsumi Hyouka as Ran]], Komoe as Pepe, [[Creator/NobuhikoOkamoto Accelerator as Musashi]], and [[Creator/RieKugimiya Agnese as Yua]].
** [[Creator/RieKugimiya Agnese]] and [[Creator/AyakoKawasumi Laura Stuart]] have appeared together many times before: [[CandidateForGoddess Ikhny and Kazuhi]], [[LightNovel/BludgeoningAngelDokuroChan Sabato and Shizuki]], [[LightNovel/ShakuganNoShana Shana and Kazumi]], [[LightNovel/TheFamiliarOfZero Louise and Henrietta]], [[Anime/{{Potemayo}} Nene and Mikan]], [[KyouranKazokuNikki Mujaki and Eru]], [[Manga/HayateTheCombatButler Nagi and Athena]], [[LightNovel/LadiesVersusButlers Kaoru and Tomomi]], [[LightNovel/OokamiSan Mimi and Otsuu]], and [[LightNovel/AriaTheScarletAmmo Aria and Jeanne]].
** ''Manga/MaidSama'' and this series have a ''ton'' of overlapping voicing: [[Creator/AyumiFujimura Seiri as Misaki]], [[Creator/NobuhikoOkamoto Accelerator as Usui]], [[Creator/AtsushiAbe Touma as Hinata]], [[Creator/KanaHanazawa Sakura as Erii]], [[Creator/AyakoKawasumi Laura as Minako]], [[Creator/AkiToyosaki Uiharu as Satsuki]], [[Creator/KanaAsumi Hyouka as Honoka]], [[Creator/MariyaIse Lucia as Erika]], [[Creator/KanaUeda Mii as Subaru]], and [[Creator/HarumiSakurai Awaki as Sayu]].
** RoKyuBu has ''nearly'' all voice actors from ''Index'' and ''Railgun''.
** Half of the Japanese female voice cast (and some of the male cast, too) worked together in ''Anime/QueensBlade''.
** Both the Japanese and English casts share several actors with ''LightNovel/OokamiSan''.
** [[Creator/BrittneyKarbowski Mikoto]] and [[Creator/MonicaRial Index]]'s dub actors were Black Star and Tsubaki in ''Manga/SoulEater''. [[MicahSolusod Toma's VA]] also played Soul himself.
** As it is also produced by the same studio, ''Manga/{{Bakuman}}'' also features a lot of voice actors from the Toaru series.
* StarMakingRole: This series did this for Creator/AtsushiAbe as Touma and Creator/NobuhikoOkamoto as Accelerator. ''Manga/ACertainScientificRailgun'' made Creator/SatomiArai (Kuroko) into a star also. Earning them Best Rookie actor (2010, 2009) and Best Supporting Actress respectively.
** And Creator/AiKayano as well. Guess her character's PopularityPower helps...
* TheWikiRule: [[http://toarumajutsunoindex.wikia.com/wiki/Toaru_Majutsu_no_Index_Wiki Toaru Majutsu no Index Wiki]]
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