* DevelopmentGag: In ''[=ReBirth=];1'', when Neptune, joking obviously, says "Iffy" must mean "I Feel For You" (as in IF loves her), Compa says they should call her "Ai", as that's Japanese for love. IF's Japanese name is "Aiefu" and she's called "Ai-chan" in the Japanese version. (The original Japanese dialogue for this scene had Compa call her "Love-chan" instead).
** A running gag in the game is that most people have inexplicable difficulty pronouncing Neptune's name. On one occasion, it's accidentally rendered "Neptunia." This is a Development Gag rather than a form of TitleDrop because it's also the case in the original Japanese voice track, where Neptunia isn't part of the title -- the last word of the Japanese title for the series is simply "Neptune", after the protagonist, but it was changed to "Neptunia" for overseas release, which this references.
* HeyItsThatVoice: Virtually ''everyone'' playable in this game!
** [[Creator/RieTanaka Neptune/Purple Heart]] is [[GundamSeed Lacus Clyne]], [[RozenMaiden Suigintou]], and [[VideoGame/{{Persona 3}} Mitsuru Kirijo]].
*** [[Creator/MelissaFahn English Neptune/Purple Heart]] is [[DigimonTamers Rika Nonaka]], [[Anime/CowboyBebop Ed]]… or a [[GhostInTheShell Tachikoma]].
** [[Creator/AsamiImai Noire/Black Heart]] is [[VideoGame/BlazBlue Tsubaki Yayoi/Izayoi]] and [[VideoGame/TheIdolMaster Chihaya Kisaragi]].
*** [[Creator/ErinFitzgerald English Noire/Black Heart]] is [[VideoGame/{{Darkstalkers}} Morrigan Aensland]], [[Series/BlazBlue Bullet]], [[Manga/RanmaOneHalf Kodachi Kuno]], [[VideoGame/{{Skullgirls}} Parasoul]], and [[VideoGame/{{Persona4}} Chie Satonaka]].
** [[Creator/RinaSato Vert/Green Heart]] is [[VisualNovel/UminekoNoNakuKoroNi Ange Ushiromiya]] and [[Manga/MinamiKe Haruka Minami]]. Also a RelationshipVoiceActor to the seiyuu below.
*** [[Creator/TaraPlatt English Vert/Green Heart]] is [[VideoGame/{{Persona 3}} Mitsuru Kirijo]] and [[VisualNovel/FateStayNight Caster]].
** [[Creator/KanaAsumi Blanc/White Heart]] is [[AmagamiSS Miya Tachibana]] and [[{{Working}} Popura Taneshima]].
*** [[Creator/WendeeLee English Blanc/White Heart]] is [[LightNovel/HaruhiSuzumiya Haruhi Suzumiya]], [[Manga/LuckyStar Konata Izumi]], [[VideoGame/Persona4Arena Fuuka Yamagishi]]… [[ManOfAThousandVoices and a lot of other people]].
** [[KaoriMizuhashi Nippon Ichi]] is [[VideoGame/DisgaeaHourOfDarkness Laharl]] and [[NipponIchi Asagi]]. Seems to be a RunningGag [[ActorAllusion with the seiyuu, seeing as she has voiced a lot of Nippon Ichi characters.]]
*** [[Creator/MichelleRuff Nisa]] is [[VideoGame/StreetFighterIV Crimson]] [[VideoGame/MarvelVsCapcom3 Viper]], [[VideoGame/DisgaeaHourOfDarkness Etna]], [[VideoGame/{{Persona3}} Yukari Takeba]], and [[VideoGame/{{BlazBlue}} Carl Clover]]. Makes sense, since she too has voiced a lot of Nippon Ichi characters.
** [[Creator/KanaUeda IF]] is [[VisualNovel/FateStayNight Rin Tohsaka]] and [[VideoGame/BlazBlue Rachel Alucard]].
*** [[Creator/KateHiggins English IF]] is [[Manga/{{Naruto}} Sakura Haruno]], [[Anime/CodeGeass C.C.]], [[Videogame/DeadOrAlive Tina Armstrong]], and [[SoulSeries Natsu]].
** [[Creator/NatsukoKuwatani Gust]] is [[RozenMaiden Suiseiseki]] and [[LightNovel/HaruhiSuzumiya Ryouko Asakura]].
*** [[Creator/CassandraLee English Gust]] is [[{{K-ON}} Ritsu Tainaka]], [[Anime/PuellaMagiMadokaMagica Kyubey]], and [[Videogame/DeadOrAlive Lei-Fang]].
** [[KanakoSakai Compa]] [[CaptainObvious (short for Compile Heart)]] is [[VideoGame/ArTonelico Shurelia]] and [[{{REC}} Aka Onda]].
*** [[Creator/CristinaValenzuela English Compa]] is [[ShinryakuIkaMusume Nagisa Saito]], [[Franchise/LyricalNanoha Nanoha Takamachi]], [[VideoGame/BlazBlue Noel Vermilion/Mu-12, Nu-13, Lambda-11]], [[spoiler:[[VideoGame/BlazBlue Saya]]]], [[{{Skullgirls}} Cerebella]], and [[Anime/PuellaMagiMadokaMagica Homura Akemi]].
** [[MikaKanai Histoire]] is [[Anime/AfterWarGundamX Tiffa Adil]] and [[Anime/CodeGeass Kaguya]].
*** [[StephanieSheh English Histoire]] [[ActingForTwo and Financier]] are [[Manga/{{Naruto}} Hinata Hyuga]], [[{{K-ON}} Yui Hirasawa]], [[VideoGame/{{Persona3}} Metis]], and [[LightNovel/HaruhiSuzumiya Mikuru Asahina]].
** [[Creator/ChiakiTakahashi Magiquone]] [[ActingForTwo and Magic The Hard]] are [[VideoGame/BlazBlue Litchi Faye-Ling]] and [[KimiGaNozomuEien Mizuki]].
*** [[Creator/LauraPost Arfoire and English Magic]] are [[LeagueOfLegends Ahri]] and [[VideoGame/{{Skullgirls}} Valentine]].
** [[Creator/KanaeIto Red]] is [[ShugoChara Amu Hinamori]], [[ShinryakuIkaMusume Sanae Nagatsuki]] and [[MayoiNekoOverrun Fumino Serizawa]].
** [[{{Nao}} 5pb.]] is the founding member and former vocalist of [[Music/{{Fripside}} fripside]].
*** [[Creator/MelaLee English 5pb.]] is… ''also'' [[VisualNovel/FateStayNight Rin Tohsaka]] and [[VideoGame/BlazBlue Rachel Alucard]].
*** ...[[TheOtherDarrin except in]] ''mk2'', [[Creator/JulieAnnTaylor where she's]] [[VideoGame/SakuraWarsSoLongMyLove Ratchet Altair]] and [[VideoGame/BlazBlue Tsubaki Yayoi]].
* mk2 adds the following to the list:
** [[Creator/YuiHorie Nepgear]] is [[Manga/LoveHina Naru Narusegawa]], [[VideoGame/{{Persona4}} Chie Satonaka]], [[VisualNovel/{{Kanon}} Ayu Tsukimiya]], [[Manga/FruitsBasket Tohru Honda]], [[Anime/SenkiZesshouSymphogear Serena Cadenzavna Eve]], and [[Anime/DogDays Millhiore Filliano Biscotti]].
*** [[Creator/ChristineMarieCabanos English Nepgear]] is [[ShinryakuIkaMusume Squid Girl]], [[Anime/PuellaMagiMadokaMagica Madoka Kaname]] and [[Manga/{{KON}} Azusa Nakano]].
** [[Creator/EriKitamura Uni]] is [[Anime/PuellaMagiMadokaMagica Sayaka Miki]] and [[VideoGame/StreetFighterIV Juri Han]].
*** [[Creator/SarahWilliams English Uni]] is [[Anime/PuellaMagiMadokaMagica Sayaka Miki]] [[RelationshipVoiceActor too]] and [[VideoGame/{{Skullgirls}} Peacock]].
** [[Creator/YuiOgura Rom]] is [[Anime/DotHackQuantum Hermit]] and [[LightNovel/{{Campione}} Athena]].
*** [[Creator/ErikaLenhart English Rom]] is [[VideoGame/StarOceanTheLastHope Sarah Jerand]] and [[VideoGame/TheLastRemnant Irina Sykes]].
** [[Creator/KaoriIshihara Ram]] is [[AriaTheScarletAmmo Reki]] and [[Manga/MaidSama Suzuna Ayuzawa]].
*** [[Creator/ShelbyLindley English Ram]] is [[ShinryakuIkaMusume Chizuru Aizawa]], [[KOn Mugi Kotobuki]] and [[MagicalGirlLyricalNanohaAs Shamal]].
** [[Creator/YukoSanpei Kei Jinguji]] is [[EurekaSeven Renton Thurston]] and ''Seikon No Qwaser's'' Sasha.
** [[Creator/YukaKomatsu Chika Hakozaki]] is [[FreshPrettyCure Setsuna Higashi/Cure Passion]] and [[Anime/PantyAndStockingWithGarterbelt Scanty]].
*** [[Creator/MichelleAnnDunphy English Chika]] is [[{{K-ON}} Jun Suzuki]], [[MagicalGirlLyricalNanoha Momoko Takamachi]], and [[VideoGame/{{Persona 4}} Margaret]].
** [[Creator/AkemiKanda Falcom]] is [[MahouSenseiNegima Asuna Kagurazaka]], [[LightNovel/{{Baccano}} Czeslaw Meyer]], and [[VideoGame/{{Persona 4}} Nanako Dojima]].
*** [[Creator/XantheHuynh English Falcom]] is [[ShinryakuIkaMusume Sanae Nagatsuki]], [[Manga/{{K-ON}} Ui Hirasawa]] and [[LightNovel/ZeroNoTsukaima Siesta]].
** [[Creator/KenjiroTsuda Judge The Hard]] is [[Anime/YuGiOh Seto Kaiba]] and [[Manga/KatekyoHitmanReborn Adult Lambo]].
*** [[Creator/KyleHebert English Judge]] is [[TengenToppaGurrenLagann Kamina]], [[VideoGame/StreetFighterIV Ryu]], [[Anime/{{Naruto}} Kiba Inuzuka]], [[Anime/DragonBallZ teen!Gohan]], [[Anime/MobileSuitGundamUnicorn Yonem Kirks]], [[VideoGame/{{Persona 4}} Mitsuo Kubo]], and [[Anime/TekkenBloodVengeance Kazuya Mishima]].
** [[Creator/KentaroIto Brave The Hard]] is [[Manga/{{Bleach}} Renji Abarai]] and [[{{Demonbane}} Kurou Daijuuji]].
*** [[Creator/DavidVincent English Brave]] is [[Manga/{{Bleach}} Grimmjow Jeagerjaques]], [[VideoGame/BlazBlue Jin Kisaragi, Hakumen]], [[Videogame/DeadOrAlive Eliot]], [[VideoGame/TalesOfGraces Richard]], and [[{{Tekken}} Marshall and Forest Law]].
** [[Creator/YojiUeda Trick The Hard]] is [[Manga/{{Basilisk}} Saemon Kisaragi]] and [[KotetsushinJeeg Senjirou Shiba]].
*** [[Creator/DerekStephenPrince English Trick]] is [[Manga/LoveHina Keitaro Urashima]] and [[VideoGame/{{Persona3}} Takaya Sakaki]].
** [[Creator/JunkoMinagawa Linda]] is [[Anime/CodeGeass Cornelia Li Brittania]] and [[{{Catherine}} Erica Anderson]]. [[spoiler: She's also Trisha and Astaroth in that game, but we'll let you figure out why]].
** [[{{Neeko}} Warechu]] is [[Manga/KatekyoHitmanReborn Reborn himself.]]
** [[Creator/LaurenLanda English Cave]] is [[VideoGame/BlazBlue Litchi Faye-Ling]], [[Anime/PuellaMagiMadokaMagica Kyouko Sakura]], [[SoulSeries Yan Leixia]], and [[Videogame/DeadOrAlive Kasumi]].
* And Neptunia V adds a few more:
** [[Creator/KanaHanazawa Pururut/Iris Heart]] is [[VideoGame/{{Persona 4}} Marie]], [[LightNovel/{{Bakemonogatari}} Nadeko Sengoku]], [[LightNovel/{{Durarara}} Anri]], [[VisualNovel/SuperDanganRonpa2 Chiaki Nanami]], [[Anime/DogDays Noire Vincaccao]], and [[Manga/KotouraSan Yuriko Mifune]].
*** [[Creator/CheramiLeigh Plutia]] is [[MugenSouls Syrma]], [[LightNovel/ShakuganNoShana Shana]] and [[Manga/FairyTail Lucy Heartfilia]].
** [[Creator/KiyoyukiYanada Akudaijin]] is [[VideoGame/MarvelVSCapcom3 Mike Haggar]], [[SlamDunk Takenori Akagi]], and [[VirtuaFighter Taka-Arashi]]. Him voicing an evil Member of Parliament is nothing new, as he has also been [[Series/EngineSentaiGoOnger Yogostein and Yogoshimacritein]].
*** [[Creator/KeithSilverstein Mister Badd]] is [[VideoGame/StreetFighterXTekken Bryan Fury]], [[VideoGame/SoulSeries Zasalamel]], [[VideoGame/DeadOrAlive Zack]], [[VideoGame/PersonaQShadowOfTheLabyrinth Zen]], and [[VideoGame/{{Persona 2}} Tatsuya Suou]].
** [[Creator/PatrickSeitz Copypaste]] is [[VideoGame/BlazBlue Ragna the Bloodedge]], [[{{Tekken}} Bob Richards]], [[SoulSeries Cervantes de Leon]], [[Videogame/DeadOrAlive Bass Armstrong]], [[EurekaSeven Charles Beams]], [[EternalSonata Frederic Chopin]], [[{{Manga/Bleach}} Isshin Kurosaki, Sentaro Kotsubaki, Kenpachi Zaraki]], [[VideoGame/SengokuBasara Chosokabe Motochika]], [[VideoGame/Persona4Arena Hi-no-Kagutsuchi]], [[VideoGame/StarcraftII Artanis]], [[{{Berserk}} Pippin]], [[AxisPowersHetalia Germany]], [[VideoGame/CastlevaniaJudgment Dracula]], [[ManOfAThousandVoices and]] [[Franchise/MortalKombat Scor]][[VideoGame/InjusticeGodsAmongUs pion]].
** [[Creator/AoiYuki Peashy]] is [[Anime/SenkiZesshouSymphogear Hibiki Tachibana]], [[Anime/PuellaMagiMadokaMagica Madoka Kaname]], [[Anime/DogDays Couvert Eschenbach Pastillage]], [[VideoGame/BlazBlue Platinum the Trinity]] and [[Anime/MusouKakyouASummerDaysDream Youmu Konpaku]]
*** [[Creator/SandyFox English Peashy]] is [[VideoGame/DisgaeaHourOfDarkness Flonne]] and [[VideoGame/PhantomBrave Marona]].
** [[KiraBuckland English MarvelousAQL]] is [[LightNovel/AccelWorld Kuroyukihime]] and [[MugenSouls Chou Chou]].
* MarthDebutedInSmashBros: As ''SteinsGate'' wasn't released in North America until after this game, [[spoiler: Kurisu Makise, Mayuri Shiina, and Itaru Hashida]] ALL made their North American debut in this game as 5pb's Skills.
* NamesTheSame: This Black Heart is definitely not [[Comicbook/GhostRider the son]] [[VideoGame/MarvelVsCapcom2 of Mephisto]] nor a boss from ''VideoGame/BattleGaregga''.
** Also Noire and Vert are not working as a QuirkyMinibossSquad [[Anime/DogDays for a lion princess]].
* NoBudget: The first game ran out of money and was mostly unfinished. The second and third games were given a higher budget and received a warmer reception.
* NoExportForYou: Sadly, Australia hasn't gotten any games past the first one. If an Australian wants ''mk2'' or ''Victory'', they'd have to import it.
** ''Vicotry'' eventually got a very small print run down under, and all three games can be purchased from PSN.
* OneOfUs: Katsuhiro Harada, the video game producer of the ''VideoGame/{{Tekken}}'' series likes Noire. And pretty much one of the main reasons why we even get Tekken in ''VideoGame/HyperdimensionNeptuniaV'' (they couldn't get the Namco name so they had to settle for this).
** And Creator/RieTanaka as well. When you can get the platinum trophies of all three games ''[[https://twitter.com/AndyTaichou/status/319266220660621312/photo/1 in the English Version]]'', you're definitely one.
* RelationshipVoiceActor: [[Creator/StephanieSheh Financier]] as [[Creator/WendeeLee White Heart's]] assistant in the first game.
** The English dub of ''mk2'' has at least 6 [=VAs=] who have worked on ''Manga/ShinryakuIkaMusume'' and ''seven'' who have worked on ''Anime/PuellaMagiMadokaMagica'' and ''Anime/KOn''.
* TheOtherDarrin: 5pb., voiced by Creator/MelaLee in the first game, is voiced by Creator/JulieAnnTaylor in the second.