Before he met Ban, Ginji was known as The Lightning Emperor, the leader of the [=VOLTS=] street gang inside the Limitless Fortress. The Four Kings were his lieutenants and close friends. In their own ways, they were all devastated when he left to form the Get Backers alongside Ban, and Shido, Kazuki, and [=MakubeX=] all resent Ban to various degrees because of it, even once they realize Ginji is happier and healthier with Ban to lean on. After Ginji left, Kazuki, Shido, and [[spoiler:Kurusu]] followed suit, leaving [=MakubeX=] to take over as the leader of [=VOLTS=] himself.


[[folder:Kazuki Fuuchouin]]
!!! Voiced by: Creator/SoichiroHoshi (Japanese), Matt Hislope (English)

Well-read, formerly one of the Four Kings of the VOLTS and really, ''really'' girly-looking—qualifies for ShesAManInJapan, ViewerGenderConfusion, DudeLooksLikeALady, ''and'' UnsettlingGenderReveal. Oddly charismatic and naïve when it comes to his personal relationships. Fights with koto strings. Nicknamed "Kazuki of the Strings" and "The Terrifying Prince". Has a tragic past, even when compared to his teammates.
* AttractiveBentGender: Unsurprising.
* BadassBookworm: Well-informed, at least. He frequently acts as the group's escort because he seems to know the most about the layout of the Infinity Fortress and many other things in general.
* BadassInCharge: He's one of the Kings. And, before that, he led his own gang, Fuuga.
* BareYourMidriff: During the Divine Design Arc
* BrainwashedAndCrazy: During the Divine Design Arc
** LightIsNotGood: [[spoiler: Controls an angel called Orpheus with the power of strings]].
* BerserkButton: Making fun of his femininity. He's almost killed someone at least twice because of this.
** He also has a ''very'' low tolerance for men who abuse women.
* BewareTheNiceOnes
* {{Bishonen}}: So much that he's mistaken for a girl.
* CharacterDevelopment: Back at the beginning of the series (and further than that in his childhood flashbacks), Kazuki has always taken much pride in his family and one of his main motivations is seeking out the Ura-Fuuchouin to avenge his family (though it's more downplayed than most instances, in that he spent most of his time (off-screen) looking for clues rather than actively hunting the Ura down). [[spoiler:Forward to the finale of the series, after multipe facedown with the Ura-Fuuchouin in the Beltline, Kazuki has learned the dark sides of his family, which prospered on the sacrifices of the Ura-Fuuchouin, and accepted the revolt that ensued from that as retribution for the sins of the Fuuchouin. He eventually takes upon himself the duty to release the Ura-Fuuchouin of the black string curse, starting with his enemies Maiya and Yuuri, and redeems his brother Yohan.]]
* DudeLooksLikeALady: The reason why.
** He's one of the primary poster boys for this trope, and this little fact is touched on several times in the series.
* ExoticEyeDesigns: [[spoiler: The same as Der Kaiser, Teshimine, Yohan and Paul]]
* {{Fanservice}}: Kazuki is weird in that Ayamine uses him to titillate both male and female readers. Don't think about that too hard.
* EvenTheGuysWantHim: Fanon mostly. But let's be honest, we REALLY ''can't'' fully blame fangirls for seeing it ''that'' way.
* EtTuBrute: Many of his former friends are introduced to the series kind of want to kill him.
* SuperpoweredEvilSide: Manga only
* EvilCostumeSwitch, MindControlEyes, SlasherSmile: While in his Orpheus persona.
* GoodIsNotSoft
* IHaveTheHighGround: Kazuki likes this trope. He pulls it on Ban and Shido while they're on a ''rooftop''.
* ImportantHaircut: Manga only.
* EyeScream: Manga-only, and he's the one making it happen for somebody else.
* GenderBlenderName: Manga-only, brain-breaking spoiler: [[spoiler:The Kazuki Fuuchouin from "normal" Shinjuku ''is very much a girl''.]]
* NamesToRunAwayFromReallyFast: Kazuki of the String and [[spoiler: Prince of Terror]].
* NiceGuy
* ThePhoenix: [[spoiler: Kazuki creates one to defeat Yohan]]
* DarkAndTroubledPast
** DoomedHometown: His family was massacred and his village was burned to the ground when he was in his very early teens.
** ParentalAbandonment: Both his parents died in the massacre.
* RazorFloss
* RapunzelHair
* ShesAManInJapan: Tokyopop's translation screwed up his very first appearance, having characters referring to him as female (not that Shido calling him a bitch wasn't funny, of course). Quickly corrected for later volumes. Lucky thing too, since there's a scene later on where Kazuki is both naked ''and'' explaining the reasoning behind his femininity.
** {{Lampshaded}} by the anime localization team in the DVDCommentary: the first one to figure out Kazuki was male was the script adapter.
* [[ShesGotLegs He's Got Legs]]: Emphasis is usually placed on his long, graceful legs.
* StupidSexyFlanders: Ginji and Ban believe they see a lady bathing in a hot spring in the distance. Ban, being the pervert that he is, gets down, and coerces Ginji to lurk alongside him to spy on the "woman". Ban manages to drag Ginji along until they're swimming right up against Kazuki's ass, and then they're attacked by a sequence of strings and needles. Immediately enough, [[CrowningMomentOfFunny they realize that they've just been trying to spy on Kazuki]].
* SugarAndIcePersonality: He's very sweet, kind, and charismatic to his teammates, but he is a deadly opponent in battle.
* TheArtifact: Yup, him too. Again, the one chance the anime ''was'' given to go into Kazuki's past and motivations, much of the actual story was omitted. For him at least, an effort was made to pluck an aspect of his past from the manga (Toshiki) and transplant it into the anime's final arc, but it was mostly a distraction to the actual story going on, and Kazuki's actual participation was minimal at best.
* TeamMom
* TranquilFury: When serious, his calm, icy demeanor is downright terrifying. There is a reason he managed to pry his way to the top of the game, making even the strongest and most valiant warriors bow down at his feet.
* ViewerGenderConfusion
* UnsettlingGenderReveal: Happens ''all the freaking time''.
** Played with in the canon, since his childhood friend Juubei thought he was a girl when they first met.
** Ren performs a [[KissOfLife Kiss of Life]] on him, assuming him to be another girl. [[CrowningMomentOfFunny Horror ensues when she realizes that this isn't the case.]]
--> '''Ren''': (enters room, sees Kazuki's bandaged, flat chest) What?! Y-y-you're a '''boy'''???
--> '''Kazuki''': And I see you're a girl.
--> '''Ren''': (throws his clothes at him) SHUT UP!

[[folder:Shido Fuyuki]]
!!! Voiced by: Creator/TakanoriHoshino (Japanese), Omar Gallaga (English)

Another of the VOLTS' Four Kings, Shido hates Ban and loves Madoka. Used to be a [[LonersAreFreaks bloodthirsty loner]], but love and Ginji made him change, so now he works as a retriever. Being from an (fictional) aboriginal tribe, Shido gets to use all their cool abilities, such as talking to animals. Nicknamed "Beastmaster".

There is a ancient feud between his [[SpeaksFluentAnimal animal-whisperer tribe]] and the insect-controlling Kiryuudo—they managed to kill off a vast majority of Shido's tribe. After the slaughter, he goes to the Limitless Fortress and eventually meets up with Ginji.
* TheArtifact: He becomes this in the anime's final arc, as there really isn't anything for him to ''do'', especially since he was probably the character most often used in filler episodes. Unlike Himiko, though, he was at least associated with the characters driving the arc.
* TheBigGuy
* SpeaksFluentAnimal, TheBeastmaster, ''and'' FriendToAllLivingThings: Animals love this guy. Notably, insects do NOT (this becomes a major plot point later in the manga).
* FacialMarkings: [[spoiler: When activating his SuperPoweredEvilSide]]
* FourIsDeath: Twice. Not only is he a member of the Four Kings, but a member of the Shiki clans—when he and the other three get together, it literally ''does'' mean death for the Kiryuudo.
* GagPenis: Implied, particularly by Ban.
** In the manga, it's practically a running joke by Ban that Shido uses his 'Horse Form' to convince Hevn to give him jobs (it's not true, of course), and that said 'Horse Form' is the only reason Madoka keeps him around (truth is debatable).
* HealingFactor: [[spoiler: Due to his SuperPoweredEvilSide]]
* HeelFaceTurn[=/=]FaceHeelTurn: Introduced as Akutsu's bodyguard who was formerly Ginji's friend.
** [[spoiler: Fakes one to get foil Kabuto's plan]]
* HeroicSacrifice: Manga-only, fortunately, he got better.
* IneffectualLoner: His back story is basically this, with Amon, Emishi and Ginji all making breakthroughs to him, but Madoka really sealed the deal. It's weird, as he averts it at the same time—with his animals, he's never ''literally'' alone.
* NotGoodWithPeople
* OfficialCouple: With Madoka.
* PoseOfSupplication: When Madoka is kidnapped and he needs Ban's help to get her back.
* RelationshipUpgrade: The very beginning of the Eternal Bond arc. Madoka finally says "I love you," and Shido reciprocates. Not that we didn't see it coming a mile off, of course.
* SuperPoweredEvilSide: [[spoiler: The Chimera]]
* TeethClenchedTeamwork: Pretty much any scene with Ban...
* ThouShaltNotKill: A promise he made to Madoka.

!!! Voiced by: Creator/MitsukiSaiga (Japanese), John Minnich (English)

The third and youngest of the Four Kings. Another incredibly intelligent and well-read character, [=MakubeX=] ends up as the de facto ruler of the Limitless Fortress, and spends his free time trying to figure out what the hell is going on there. [[spoiler:[=MakubeX=] may or may not actually exist, and that kinda drives him insane early on.]]

* BroughtDownToNormal: [[spoiler:At the end of the manga, as a result of Ginji restoring the world, MakubeX becomes a normal boy and goes shopping with Sakura. Though his computer skills likely remain.]]
* TheChessmaster
* TheCombatPragmatist
* TheCracker
* CrossdressingVoice: In Japanese, but oddly not in English (save for in one flashback).
* FourIsDeath
* GoMadFromTheRevelation: His hacking of the Brain Trust set off the events of the IL arc. See Below.
* KnightOfCerebus: The story gets much more serious with his appearance
* LetXBeTheUnknown: Makubex was abandoned as a baby and found in a bag that had "Makube" written on it. Assuming "Makube" was his surname, the X represents his given name (if he ever had one in the first place).
* LikesOlderWomen: ''Strong'' undertones of this between him and his lovely supporter Sakura. He's 14, she's 23.
* ManipulativeBastard
* MasterOfIllusion: through virtual reality.
* NonActionGuy: DoubleSubverted, he seemed to fight Ginji in the final battle of the IL arc but he turned out to be a VR.
* RapidFireTyping
* TagalongKid: Inverted. He's got three (later four) sidekicks, all in their 20's, who would follow him to the depths of hell and back again.
* TeenGenius
* TomatoInTheMirror: [[spoiler:A major point of the IL arc is him coming to terms with the fact that he's essentially a hologram who can never leave the Infinite Fortress.]]
* [[TryingToCatchMeFightingDirty Trying To Catch My Minions Fighting Dirty]]: The fights he sets up involve a lot of this, including Juubei attempting to get Kazuki InTheBack and mind controlling a bunch of kids to fight the heroes.
* WellIntentionedExtremist

[[folder:Masaki Kurusu]]
!!! Voiced by: Creator/HideyukiHori (Japanese), Robert Kraft (English)
The last of the Four Kings, and by far the most mysterious, who spends most of his time sitting around and making cryptic remarks as he spies on people. Also ''knows things''. He's the only member of the Four Kings to have come from Babylon City. Fights with light. Prior to his introduction, the other three Kings would only refer to him as "him" or "that guy" or "the other one".
* AntiVillain: Anime only, where he was actually forced to serve Brain Trust out of fear for the lower level inhabitants.
** [[spoiler: In the manga, it's more complicated]]
* BadAssLongCoat
* BecauseDestinySaysSo: [[spoiler: He [[HeelFaceTurn turned sides to the Voodoo King]] in the manga]]
* CoolOldGuy
* EvilAllAlong
* ExoticEyeDesigns: [[spoiler: He has the same cross design in his left eye as Der Kaiser, Paul and Kazuki]]
* FourIsDeath
* HiddenAgendaVillain: [[spoiler: For a long time, we didn't know what his goal was, until he reveals that he's an agent of Brain Trust and the Voodoo King]]
* HeelFaceMole: [[spoiler: more sympathetic in the anime, in the manga he's a straight out spy for the Voodoo King]]
* HeelFaceTurn
* LightIsGood
* LightIsNotGood
** {{BFS}}: Can manifest one called {{Excalibur}}
** LightningBruiser
** FrickinLaserBeams
** HardLight
** IntangibleMan
** MasterOfIllusion: Optical illusion to be exact
** PillarOfLight
* MysteriousWatcher: Mercilessly parodied by Rando Ayamine himself in one of the first page character sketches. Masaki is shown SuperDeformed, hugging his knees with tears streaming down his face while he talks about all the cool stuff he did in the anime even though he hasn't done anything but spy on people in the manga. And he wants Kagami to go drinking with him.
* NamesToRunAwayFromReallyFast: Flash Master
* TheMole: [[spoiler: For Brain Trust, as well as the Voodoo King in the manga]].
* PermaStubble
* SlapSlapKiss: [[spoiler:His romance with Hevn started like this.]]