[[quoteright:256:http://static.tvtropes.org/pmwiki/pub/images/IO_cover_1052.jpg]]
Also known as ''I/O''. This is the first original game by the company Regista, founded by Takumi Nakazawa of the ''Infinity'' series (''VisualNovel/{{Never7}}'', ''VisualNovel/{{Ever17}}'', and ''VisualNovel/{{Remember11}}'') fame, and a collaboration between Nakazawa and Romeo Tanaka (of ''CrossChannel'', ''KanaLittleSister'' and ''Yume Miru Kusuri'' fame).

''I/O'' takes place in the year 2032. A lunar eclipse occurs in late April, causing a surge of terrorist activities and bizarre incidents. As time goes on, things get worse and worse, with the key to the mystery seemed to be locked away in the MMORPG "Babylon". Four people, through their own ways, investigate the ongoing phenomenon, each one dealing with his or her own problems...

''I/O'', like the ''Infinity'' series, has multiple protagonists, in this case four. Route A features Hinata Aoi, an OrdinaryHighSchoolStudent who has become depressed after the disappearance of his twin sister, Mutsuki. Route B features Ishtar, a young woman in charge of a hacking group known as Criminal. Route C also features Ishtar, but she seems different from herself in Route B. Route D features "HE", a mysterious man who is a legend on the Internet. Once all four of their routes have been completed, they unlock Route E, the true route.

The game was originally released on the PlayStation2 in 2006, but was given an UpdatedRerelease on the PC two years later, with new [=CGs=] and slightly updated artwork (as well as giving sprites to many characters who didn't have any in the original).

A fan-translation was released by [[http://lemnis.ca/ Lemnisca Translations]] on February 22nd, 2014.
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This game provides examples of:

* ACupAngst: Masami is upset because she's flat chested and therefore not as feminine as her identical twin, who somehow ''isn't'' flat.
* AFatherToHisMen: [[spoiler:Enlil, who cares deeply for all her followers at Code, who feel a similar loyalty towards her.]]
* AIIsACrapshoot: There are [[spoiler:two quantum computers, which awaken as individuals by the very nature of their construction, much as Exarch would like to deny it.]] Saying they are ''evil'' is going too far, but they simply don't understand human values. It may not even be possible for them to understand the human viewpoint because they live in the Net while humans live in the real world and visit the Net, meaning they see no value in the real world at all.
** As it turns out in Route E, [[spoiler:Ashur, despite his initially antagonistic attitude, is motivated by gratitude to He]] while Marduk [[spoiler:has grown too paranoid and distrusting and eventually has to be disconnected from Mutsuki, even though she’s her daughter.]] In response, [[spoiler:Ashur wants nothing more than to apologize to her and eventually arranges for Ereshkigal to take Mutsuki’s place. That allows Marduk and Ashur to be together as well as He and Ereshkigal, also known as Izaiah Nagy and Izawa Nami.]]
** In Route A', they're entirely helpful. It's not like they dislike humans or want them to suffer.
** In Route B', [[spoiler:they almost cause an AssimilationPlot of sorts using Nulls and have to be shut down. It's not like they understand humans even if they don't dislike them.]]
* TheAllConcealingI: People’s identities are masked by various pronouns. [[spoiler:For example, Yumi pretends to be Ishtar much of the time and even uses her pronouns and speech style.]] Further, it becomes increasingly clear that someone else is watching the protagonists [[spoiler:and occasionally nudging them in the direction it wants them to go.]]
* AmbiguousGender- Enlil, who is never specifically identified as a man or a woman. [[spoiler:Route E finally confirms that Enlil is a woman.]]
* AngstySurvivingTwin: [[spoiler:Mayumi, though notable in that she seems to treat her sister's death on equal level with the rest of her comrades' deaths and below Ishtar's.]]
* AnyoneCanDie: The number of dead characters at the end is probably lower than the number of living ones, especially depending on how you count Nulls and whether you're ending with A' or B'. At the very least, [[spoiler:four out of five members of Criminal don't make it out, Hinata's father dies and either Mutsumi or Sakuya vanishes or dies. In B', He and Criminal die again as well as the quantum computers and Tammuz.]]
* ArcWords: Where are you? I am here!
** "The beginning is the end, and the end is the beginning."
* ArtificialHuman: Nulls and Shadow Nulls are [=AIs=] based off of dead humans [[spoiler:and includes Ea and eventually He, Ishtar and Criminal minus Yumi.]]
* ArtificialLimbs: [[spoiler:Hinata lost both legs and one arm when he was attacking by Enlil. They were replaced by Nergal along with some internal organs.]]
* ArtisticLicenseBiology: Accuracy to the biological sciences was clearly not a priority here.
** It's said at one point that only humans commit suicide. Not only is this not true, but the story goes on to say that biological imperatives are what cause lemmings to leap from cliffs. Lemmings ''don't'' leap from cliffs, they get knocked off.
** When Yayoi asks Hinata what was unusual about Einstein's brain, he says it's that he used more than ten percent of it like normal. Yayoi's only disagreement is that what she meant was that he used both hemispheres. Not only does the normal human brain do both of these things, but it misses mentioning that Einstein's brain ''was'' genuinely odd: It was malformed, specifically in that the parietal operculum was malformed and that another part of his brain grew into that area, which is speculated to be responsible for his talent at mathematics and poor language ability.
** The Hundredth Monkey phenomenon[[note]]Basically, that once a certain number of a group know how to do something suddenly they'll all know how to do it[[/note]] is not only not discredited, but accepted so thoroughly that dismissing it is about on par with dismissing gravity. Hinata refutes the theory at one point but then the story assures us that yes, it's definitely legit.
** Yumi and Masami are identical twins, but Yumi has a larger bust even after [[spoiler:losing a lot of weight after route B. Relative to what Masami had before dying, that is.]]
** Evolution is directed. It also happens extremely quickly, all at once between unrelated individuals and ''occurs preemptively.'' Also, it's intelligent or something because it's aware that four billion women somehow constitutes sufficient genetic diversity that males aren't needed anymore.
* AscendToAHigherPlaneOfExistence- [[spoiler:Some of the villains plans. This happens to Criminal at the ends of Routes E and B'.]]
* AssimilationPlot: [[spoiler:Marduk and Ashur]] in route B' attempt to absorb all of humanity [[spoiler:when they become Nulls. This isn't a problem for [=ICs=] because they're perfectly suited to live inside a computer, but a normal person can't maintain their sense of self well enough to be considered 'alive' in a computer.]] In Route E' [[spoiler:they may have succeeded.]]
* AuraVision: Ishtar's blue eye is actually blind in the traditional sense. However, she's able to see people's auras unless they're [=ICs=]. Her OneeSama, Ereshkigal, had this condition in ''both'' eyes.
* BackToBackBadasses: After their first meeting in E, Ishtar and {HE} are back to back, guns drawn. [[spoiler:Well, Yumi and Hinata, more like it.]]
* BackToFront: C is told back to front, but the perspective is actually linear. [[spoiler:So is D, but {HE} never seems to realize that. C’ is also told the same way, but actually explains events from Yumi’s past rather than story events.]]
* {{Badass}}: He is a guntoting super hacker with superhuman physical abilities.
* BadassLongcoat- Once again, "HE".
* BadDreams: Route A begins with a nightmare that the protagonist can’t remember. He remembers having to comfort someone else when they had nightmares, but then purposefully stops thinking about that.
* BadFuture: Route’s C and D involve [[spoiler:traveling back through time point by point in an attempt to avert a future where Hinata massacres Code in a berserk rage even though he should be their ally.]] Further along in this timeline would reveal that what they're trying to really avoid is [[spoiler:Nabu wiping out humanity in its current form after Mutsuki dies, which is somehow the trigger for genocide.]]
* BedmateReveal: Happens in Route D between "HE" and Ishtar, though it's clear that nothing happened between them.
* BerserkButton
** Enlil has a huge sensitive spot regarding Sin. [[spoiler:She even kills the second Sin for disgracing her name by distributing a drug that Enlil herself created.]]
** In A’ Hinata nearly strangles a man for simply running over a rabbit and not caring.
* BigBad: Enlil assassinates several of her friends, tries to kill Hinata [[spoiler:and does kill Criminal, but in the end she's on the ally side against Exarch, who are the real big bad. If anyone.]]
* BittersweetEnding
** B’ ends with [[spoiler:the Nulls, Tammuz, the quantum computers and He dead.]] On the bright side, [[spoiler:Yumi is probably going to successfully confess to Hinata soon and Mutsuki is still alive.]]
** A’ is significantly happier [[spoiler:with Sakuya being discovered and starting to go out with Hinata. His genetic sterility will probably be cured by her because apparently that was a thing. Mutsuki has vanished, however.]]
* BloodFromTheMouth: After eating little as well as smoking and drinking heavily [[spoiler:after the death of his family]], inspector Miyata looks like death and coughs out wads of blood. When he finds purpose in trying to figure out what happened and tracking down {HE}, he gets his act together a little, though he doesn't quit smoking.
* BlueAndOrangeMorality: [[spoiler:Marduk and Ashur not only have completely different values from humans, but they don’t even properly understand concepts from the mortal world like ‘physical death.’]]
* BolivianArmyCliffhanger: If you haven't cleared the routes required to see their full endings, Route B, C, and D end this way.
* BrainUploading: It's mentioned in the keywords index that people have been wondering about the idea. It ''is'' possible, too, even accidentally. Such results are known as Nulls, who are usually identical to the person that created them but lack the ability to be creative.
* BrilliantButLazy- Hinata is very intelligent and is shown to be able to solve complicated problems in seconds, but he's so apathetic towards life that he's just not interested in it (much to Sakuya's consternation).
* BringMyBrownPants- Andras at a point in Route B.
* BrotherSisterIncest- While nothing explicit happens, there's a lot of subtext between Hinata and Mutsuki, the former who is practically obssessed with the latter. Lampshaded several times, particularly where he questions Yayoi whether or not he has a sister complex.
* {{Buttmonkey}}: Kosuke tends to be constantly abused or picked on by everyone in Criminal, but his attitude suggests it’s something he allows rather than something that is forced on him. Mostly.
* CameBackWrong: [[spoiler:Ea was killed by Enlil, turning her from the one most grounded in reality to an obsessive, manipulative and almost emotionless defender of Babylon.]]
* ChekhovsGun- [[spoiler:Some seemingly throwaway bits of conversation between Hinata and Yayoi early in Route A turn out to be vital in figuring out the mystery later on.]]
* ChekhovsGunman- [[spoiler:Mayumi, who goes from being a supporting character in Routes A and B to one of the two main protagonists by the end of game.]]
* ChildhoodFriendRomance: There are two real endings to the game. The first, A', has Hinata finding Sakuya and admitting he loves her. [[spoiler:In B', he fails to save her, but it's still clear he felt the same way.]]
* ClingyJealousGirl: Sakuya for Hinata, which he eventually calls her out on.
* CloningBlues: [[spoiler:Sakuya, who is actually a clone of her former self (also named Sakuya), who was killed in a car accident.]]
* CloseEnoughTimeline: [[spoiler:In Route E, there’s so much question over what is real or not that when Mutsuki wakes up everyone decides that it doesn’t really matter if this world is real or not. It’s real enough. This much was only possible after manipulating time inside of dreams inside of dreams too. Where did those internal dreams end or begin and did they manipulate time properly?]]
* ContemplateOurNavels- The characters go into this occasionally, especially towards the end of Route E.
* CoolShades- "HE" has a pair.
* TheCracker- The cyberterrorist group "Code" is composed of these.
* CrashIntoHello- How Hinata officially meets Masami and Mayumi.
* CreativeSterility: A Shadow Null is just like the person it was based on except incapable of creative thought.
* CuteClumsyGirl: Yumi has a way of tripping and falling flat on her face. It happens most often around the full moon and rather infrequently around the new moon.
* {{Cyberspace}}
* TheDanza- Kosuke Miyata, who is played by KosukeToriumi.
* DeadAllAlong: [[spoiler:Ea, who was murdered by Enlil a year before the story begins. The Ea we see is merely her Shadow Null.]]
* DeadpanSnarker- Hinata, particularly around Yayoi and Sakuya.
** FirstPersonSmartass- The rest of the time.
* DeadPersonImpersonation: In Routes C, D and E the person pretending to be [[spoiler:Ishtar is actually Yumi]] who took up the name out of respect. In Route D, this goes undiscovered, in Route C we see that she’s been playing the role so much that she forgot it was just a role and in Route E we see how this situation came to be.
* DeathByChildbirth: Sakuya's mother died during childbirth. [[spoiler:It was a virgin birth, meaning she has no father. Nabu took her in instead and eventually grew to love her as his own daughter.]]
* DeliberateInjuryGambit: [[spoiler:To beat Enlil, He ‘stumbles’ and allows his shoulder to be slashed. With Enlil offbalance, she’s promptly knocked backward and disarmed.]]
* DeusExMachina: Invoked at the end of Route B 1.0 with [[spoiler:R calling upon the seemingly invincible He to rescue them.]] However, [[spoiler:only R, Sakuya and Nabu make it out alive when He floods the chamber with nitrogen gas to suffocate Code.]] So much for a rescue from God.
* DiabolusExMachina: At the end of B’ [[spoiler:Ishtar and the other Nulls are reincarnated into physical form, but then the quantum computers try to eat them and have to be shut down, which erases the Nulls.]]
* DifferentAsNightAndDay: Masami is bright, fiery and implied to be athletic. Mayumi is quiet, lacks self confidence and is rather klutzy.
* DisappearsIntoLight- [[spoiler:Lem, after her death.]]
* TheDitz: Much of the time, Lem is rather scatterbrained. It's worse during the new moon, but even when the moon is full she's easily distracted, goofy and pretty dumb. [[spoiler:Mutsuki has no idea how her own Shadow managed to become so airheaded, but let's it go.]]
* DoggedNiceGuy: Nergal is in love with [[spoiler:Ereshkigal]] but she loves [[spoiler:Izaiah Nagy]]. He's not happy about it, but he keeps supporting her anyway [[spoiler:right up to putting her in a tank at her request so she can stay linked to the Net and look for him.]] In one ending, he may have a chance since [[spoiler:Izaiah is gone, even as He, but Ereshkigal never died.]]
* DownerEnding: [[spoiler:Route B ends with Mika cut down by Enlil, Kosuke shot defending the Double, Hinata’s father getting headshotted and L and Ishtar suffocating when R’s plea to He results in him flooding part of the chamber with nitrogen gas to take out Code but not realizing that Ishtar and L were allies.]]
* DreamWithinADream
** [[spoiler:The first five routes are all a ‘dream’ someone is having in an attempt to remedy their own version of the problem in their world. That’s why people can travel backward and forward in time and the phase of the moon makes no sense in route E.]]
** [[spoiler:Whether or not the story ends in the place where it began or a stage or two above that, that world might not have been reality either. The ‘real world’ has invented cyberspace, which is increasingly populated by Imaginary Children. Those Imaginary Children populate Cyberspace as it feels more real to them so long as it’s based on reality rather than some extravagant fantasy. From there, it’s easy to guess that eventually that world WILL be reality to them. Maybe another group will eventually feel that world isn’t real enough for them and make another dream within the dream.]]
** Piecing together what is real in the end is largely a matter of opinion, especially when E' rolls around.
* DrivenToSuicide: [[spoiler:Frustrated at being caged in and only allowed at for fifteen minutes every two weeks, Izaiah Nagy uploaded his mind to the Net and then overloaded his biocomputer, burning out his brain.]]
* DroppedABridgeOnHim: The most natural way to play through the story involves doing route C 0.1 before completing route 1.0. However, doing this results in the nasty shock that [[spoiler:Criminal never made it out of that lab. Only Yumi survived while Ishtar and the others died offscreen.]] After this, though, when you eventually get to B 1.0 you'll see how it actually happened. It's sad not just because [[spoiler:Criminal and Aoi's father die]] but because [[spoiler:there was no reason Masami and Ishtar had to die except that He screwed up and Yumi was in too much pain to realize.]]
* DrowningMySorrows- [[spoiler:Mr. Miyata, Kosuke's father, does this for several months after the death of his son. Notable in that its mentioned he originally quit drinking and smoking after Kosuke was born.]]
* DualityMotif: Ishtar’s eyes. One eye sees only reality. The other sees only the Net.
* DyingDeclarationOfLove: In Route B' [[spoiler:Tammuz dies in front of Enlil]] confessing that he had always loved her, but knew it wouldn't have been possible [[spoiler:with Mutsuki in the picture. Enlil]] says that without that wrinkle it could have turned out better between them. Not long after [[spoiler:Kosuke's Null is killed protecting Yumi]] and he confesses to her. Yumi is warned to learn the lesson these two failed to grasp [[spoiler:and get your feelings across ''before'' you die. She does.]]
* EasilyForgiven: Played with. [[spoiler:The story says that Enlil, Hinata, Ishtar, Yumi and He all forgive each other, but in truth it’s more along the lines of ‘I’ll stop hating you so much that we can't accomplish our mutual goals.']]
* ElectronicEyes
** Ishtar’s blue eye is an electronic eye that can see cybernetic things and people’s auras [[spoiler:but only in Route C, where she’s actually Yumi after her eye was shot out. The real Ishtar was born with an eye that could do that. Otherwise it’s essentially blind.]]
** Enlil had her eyes replaced after Ishtar and Ereshkigal became close. Apparently, she felt left out.
* EmergencyTransformation- [[spoiler:Hinata is forced to have 2/3rds of his body replaced with mechanical parts in order to save his life after being severely wounded by Enlil.]]
* EvilInc: Exarch is guilty of murder, extortion, bribery, human experimentation, human trafficking, arms smuggling, running monopolies, creating addictive drugs that can't be detected as narcotics, selling said drugs, terrorism and more.
* {{Expy}}: WordOfGod says that Ishtar and Enlil's costume/character designs were inspired by Julia and Vicious from CowboyBebop, whereas "HE"'s outfit was inspired by Neo's from TheMatrix.
* EyeScream: [[spoiler:Yumi loses an eye in the battle where everyone else in Criminal loses their lives.]]
* EyesAlwaysShut- Ningirsu.
* FaceHeelTurn: [[spoiler:The Nulls of Criminal turn against Ishtar/Yumi and Hinata/He in route E, though since they unwisely chose Kosuke to keep an eye on Yumi he fails to keep her hostage properly and not much comes of it. In B’, they switch back to Ishtar and Yumi’s side.]]
* FakingTheDead: Route E reveals that Hinata and Yumi are officially dead [[spoiler:after Criminal was wiped out defending Exarch and Hinata was mortally wounded by Enlil.]]
* FashionableAsymmetry: Ishtar's bangs are of completely different length. Her eye colors don't match either.
* FeminineWomenCanCook: Yumi knows how to cook, Masami doesn't. The latter is frustrated because Kosuke is obviously much more interested in Yumi than her.
* FirstLove: These pretty much never work out in the story. One person or the other tends to die or disappear, even the rock solid [[spoiler:Enlil and Mutsumi]] relationship.
* ForgottenFallenFriend- [[spoiler:While not exactly fallen, Hinata pretty much never gives Sakuya any thought after he leaves her after Route A, but is eventually subverted in Route A', where his main focus becomes finding her. Averted with Mayumi, as she frequently thinks about death of her comrades.]]
* ForScience: Nabu is not particularly concerned with what anyone actually ''wants'' with a quantum computer. He just wants them to exist. In fact, he pretty much ''only'' cares about science [[spoiler:with his daughter Sakuya being the single exception in his entire life.]]
* FriendlyFire: [[spoiler:Masami and Ishtar are killed when {HE} comes to rescue Criminal, Nabu and Sakuya, but sends down a partition in the wrong area and suffocates them with nitrogen gas.]]
* FutureBadass: [[spoiler:In Routes C and D, "Ishtar" and {He} are Yumi and Hinata respectively after they've partially merged with the real Ishtar and Izaiah Nagy's fragmented Null.]]
* GainaxEnding: Route E' is the final route unlocked and is largely unconnected from the preceding story. It functions more as exposition, but seems to be a world in which [[spoiler:everyone is still alive, but the world may not be real.]]
* GenderBlenderName- Enlil's real name, Tsukasa, is a name usually given to boys. When Hinata hears her name, he assumes she's a man.
* GenkiGirl
** Lem, the Babylon mascot, is a bubbly and energetic spaz.
** Ishtar is goofy and energetic, but in truth she's mostly a {{hikikomori}} and isn't really as cheerful as she acts.
* TheGhost
** Ishtar’s OneeSama is mentioned often in Route B, but she doesn’t appear, nor is she named. Eventually, the list of people she could be is reduced such that there’s nobody in the cast she could be, at which point she’s revealed to be Ereshkigal, a programmer who left the Babylon staff years ago. She eventually does appear. [[spoiler:Plus, she was the serious LEM all along.]]
** Shamash was one of the members of Anunnaki, but apart from one line describing what he did he never actually appears in any flashbacks of the group where they attempted to establish the policy for the group. Eventually, it turns out that there's a good reason he never appears in their flashbacks: He never actually met them and was basically just an Exarch consultant watching over the master computer Marduk. [[spoiler:His real world counterpart is Hinata’s father, though.]]
* GirlInABox: [[spoiler:Mutsumi is dreaming inside a special life support pod that connects her to the Enigma system that supports the world of Babylon.]]
* GogglesDoNothing- Route C Ishtar wears a pair of goggles/sunglasses on her head that she never wears.
* GreyAndGreyMorality
** Criminal named their group after the idea. Namely, they're trying to do good things (for money, usually) but know that they're skirting the borders of legality. Kosuke is there to keep them from falling into black morality.
** For the story as a whole, there aren't really any entirely evil characters, though Enlil and Nabu are very dark. [[spoiler:One murders her friends for unclear reasons, the other assists in an AssimilationPlot because he thinks it would be interesting.]]
* GroundhogDayLoop: The story starts somewhere and ends somewhere and repeats itself sometimes. Where any of those points are is rather ambiguous.
* GuideDangIt- This game is incredibly difficult to clear if you have no idea what you're doing.
** Specifically, there are initially four routes. Sounds simple enough. What the game doesn't tell you is that you have to get a certain other ending to see the full ending of another route. If you don't, then you are left at a "cutoff point", which seems like the ending, but isn't. (In order to see Route A's full ending, you have to clear Route C, Route D must be cleared to see Route B's full ending, Route B needs to be cleared for Route C's ending, and Route A needs to be cleared for Route D's ending). Then you unlock Route E, which, if you clear that, opens up four new routes which must be cleared, and it is then and only then that you can see the True Ending. Sound complicated?
* GunsAkimbo- "HE"'s main style of fighting, with a Desert Eagle in his right hand and a Colt Government in his left. Unlike most examples, however, he usually only focuses on firing one gun at a time.
* GunPorn- One scene in particular in Route D is practically devoted to discussing the specs of "HE"'s weapons in great detail.
* HalfIdenticalTwins: [[spoiler:Hinata and Mutsuki, the latter of whom had their Y chromosome degenerate so much that she ended up female. Both are sterile due to that chromosome.]]
* HandWave: The story admits that the Hundredth Monkey theory has been discredited, but then goes on to basically say “But what if it was really true?” It’s accepted as an obvious fact. [[spoiler:Hinata attempts to deny it once, but then nope! It’s true after all.]]
* HangingSeparately: Enlil is ridiculously aggressive and unwilling to listen to anyone, meaning she causes more damage than [[spoiler:her mutual enemy with Hinata, Exarch.]]
* HatesBeingAlone: Ishtar is an IC and doesn’t really get along well with normal people, but she also gets upset and lonely when she’s by herself. Ereshkigal was the first person to notice this about her and helped Ishtar become more like the friendly and upbeat person she acted like. However, she still needs to be around people to not be an emotional wreck.
* TheHeart
** Ereshkigal was the first person to appear in Babylon after the Triad and became one of the Anunnaki, but she contributed almost nothing in the way of code. According to Nergal, she mostly functioned as an emotional core for the group even though as a hacker and programmer she was at least as good as Enlil.
** Kosuke was the only non IC member of Criminal and as a result the most grounded in the real world. After initially being coerced into joining, he decided he liked the group and what they did provided they kept themselves clean. He stayed to keep an eye on them.
* [[spoiler:HeelFaceTurn]]- [[spoiler:Enlil.]]
* HeKnowsTooMuch: [[spoiler:The Double’s father, Takuya, was in charge of an Exarch project to create a quantum computer. When he finished it, he and everyone else involved died in a tragic accident that left it impossible to recover their bodies.]]
* TheHeroDies: [[spoiler:Ishtar doesn’t survive Route B. For the most part.]]
* HeroicSacrifice:
** Subverted in Route B': [[spoiler:Ningirsu attempts to do this by letting his teammates go ahead while he's stuck next to dynamite, but it's subverted when the sprinklers in the building activate, defusing the dynamite.]]
** In Route B' for real [[spoiler:the Nulls of Criminal are incarnated, but destroy the quantum computers maintaining them because they pose a danger to normal humans. They all presumably die instead of simply returning to being data.]]
* HeWhoFightsMonsters: Enlil is fighting Exarch. Okay, sure, whatever, but then she goes on to [[spoiler:assassinate her old friends and the families of people who opposed her for no real reason.]]
* HeyItsThatVoice
** Perhaps due to Romeo Tanaka's influence, this game shares several voice actors with Yume Miru Kusuri, such as Michihiko Hagi (who voices Hinata in I/O and Takeshi in YMK), Ryoko Tanaka (who voices Sakuya in I/O and Mizuki in YMK), and Kayo Nagata (who voices Mutsuki in I/O and Nekoko in YMK). Incidentally, the two games were released a month apart from each other.
*** Hinata is also [[FireEmblemTellius Ike]].
* HeyYou: He tends not to use any names, which bugs Ishtar.
* {{Hikikomori}}
** Mutsuki before disappearing had become increasingly isolated from the world after Hinata told her that an 'ugly rabbit' would never become a beautiful white one unless it had the potential all along. He wasn't referring to her, but that's how she took it.
** Ishtar is bright and friendly, but she also never leaves her apartment unless Mika or the others drag her out.
* HopeSpot- [[spoiler:At the end of Route B, it looks like Criminal and the others are finally going to make it to the helicopter pad... and then Hinata's father gets shot. [[DownerEnding It all goes downhill from there.]]]]
* HowWeGotHere: Route E begins the explanation for [[spoiler:how Hinata became He and Yumi started remaking herself in Ishtar’s image. From there, we learn how Hinata came to declare war on Enlil and Inanna ended up as the leader of Code.]]
* HypocriticalHeartwarming
** Masami is rather dismissive of her sister, but she gets really angry when people call her slow or stupid. Only her own sister can call Yumi names like that.
** Enlil derides Ishtar for carrying the rosary as a memento from Ereshkigal, but Yayoi points out that she made a rosary of her own.
* IJustWantToBeNormal: More than wishing she had good health, Mutsuki wishes people would treat her like normal. Further, she hates that while they're both [=ICs=], only Hinata was able to become social and popular while she decided that she would remain ugly and unappreciated forever.
* IllGirl: Mutsuki has been sick most of her life. It's not really important except that it causes people to try spoiling her, which she absolutely hates. Especially when nobody spoils Hinata, who just has to suffer for her sake as far as everyone else is concerned. She makes him promise to never give her special treatment.
* ImprobablyFemaleCast: There are only a handful of male characters in the story, even fewer of them particularly important. [[spoiler:[=ICs=] tend to be female and the population balance of the world is quickly skewing in favor of women as well. Since the majority of the cast are main characters because they’re [=ICs=] it’s no wonder that there are so few males.]]
* IWantMyBelovedToBeHappy- [[spoiler:Mayumi acknowledges that while she loves Hinata, he has Sakuya, and so she resolves to let them be happy together. However, in the ending of Route B', where Hinata is unable to save Sakuya, it's implied that Mayumi will eventually confess to Hinata.]]
* InferioritySuperiorityComplex- [[spoiler:Masami, who's haughty attitude is used to hide the fact that she feels inferior to her sister Mayumi, who is more loved by the rest of the members of Criminal. Ironically, Route C' reveals that Mayumi also felt inferior to Masami.]]
* InformedAttribute: Identical twin [=ICs=] are very rare [[spoiler:but we have two different pairs in the main cast. Setting aside Yumi and Masami, Mutsuki and Hinata should both be male, but Mutsuki’s degenerate Y chromosome didn’t activate properly.]]
* ItsNotYouItsMyEnemies- [[spoiler:Hinata uses a variation of this to leave Sakuya.]]
* ItsPersonal: [[spoiler:The members of Code are mostly made up of people whose families worked at eXarch and were killed to protect their secrets. On top of that, eXarch experiments on people like them and sells them addictive drugs that are only supposed to be immunosuppressants.]]
* JapaneseRanguage- Actually used as a plot point once. [[spoiler:When trying to solve Mutsuki's crossword puzzle, Hinata can't figure out the clue for the word "Lunar Excursion Module" due to the lack of an L in Japanese, and so is stumped until Mayumi helps him. She even lampshades the trope.]]
* JapanesePronouns: A plot point in that [[spoiler:Each protagonist uses a different one, which gets its own emphasis. Hinata is the polite masculine boku, Ishtar is the playful feminine atashi, Mayumi is generally a ThirdPersonPerson and He is the gruff male ore.]] In route D’ [[spoiler:we see He slowly slip backwards in time to discover his origins. His pronoun use quietly shifts to boku as he returns to someone who was like Hinata.]]
* JerkWithAHeartOfGold: Nergal only cares about money, but he’s surprisingly weak to direct emotional appeals if pulled off well. He also has a huge soft spot for Ereshkigal and a minor one for Ishtar.
* JourneyToTheCenterOfTheMind: [[spoiler:Hinata and Mayumi have to do this to awaken Mutsuki by diving into her brain in the Enigma system. However, this gets them trapped into an infinite loop by "Marduk".]]
* KaleidoscopeEyes: After Route B, Yumi still has her natural eye colors [[spoiler:except when she’s impersonating Ishtar or granting her some control, which makes her electronic left eye turn blue.]]
* KillEmAll: [[spoiler:Route B ends with Mika being cut down by Enlil. The extended ending shows that Kosuke takes a few bullets for the Double and dies, Aoi's father is shot in the head and Masami and Ishtar are killed when a badly wounded Yumi calls out for {He} but in her pain doesn't realize {He} sent down a wall partition with those two on the wrong side.]]
* LegacyCharacter
** Hinata succeeds the name Shamash in route A, though he has no idea whose handle he's borrowing. Ea is stunned to see this, especially since she knows that Hinata is far too young to be the real Shamash, but all the data checks out regardless.
** The original Sin disappeared a few years ago without telling any of her original friends. Ishtar is briefly saddened by the news that Sin is a drug dealer before learning that it's not the same girl she knew. [[spoiler:Then that Sin is killed by Enlil and replaced with Andras.]]
** After route B [[spoiler:Yumi begins acting like Ishtar and even sort of hosts her Null inside her biocomputer.]] The real [[spoiler:Ishtar]] was killed when the hallway she was in was flooded with nitrogen.
* LongLostRelative: [[spoiler:Ishtar's birth mother is Shinobu Shinozuka, making Mayumi and Masami her sisters. However, none of them know this, nor do they ever learn it.]]
* LoveAtFirstSight
** In Route B' we find out Tammuz fell in love with Enlil upon seeing her dedication, but knew that with Sin around he never stood a chance. [[spoiler:He can't admit this until he's already dying and Enlil sends him off by saying that things could easily have been different between them.]]
** Izaiah Nagy and Izawa Nami both fell for each other at first sight. Or rather, the former did while the latter [[spoiler:is the blind Ereshkigal, who can't even see his aura since he's an IC but fell for him anyway.]]
* LoveDodecahedron: Masami -> Kosuke -> Yumi -> Hinata -> Sakuya, though route B' ends up with him and Yumi together. Ishtar drily notes in her internal monologue at one point that this is one of those situations that's fun to see from the outside but would be hell to be involved with.
* LoveEpiphany: [[spoiler:Mayumi has one in Route B', where she realizes she loves Hinata.]]
* LoveMakesYouStupid: The greatest hacker in the world was caught when [[spoiler:he cracked into Exarch and stole money by making a fake project]] to get biocomputer surgery to look for the girl he loved, Izawa Nami. He was too focused on this to do a proper job of hiding his tracks.
* LoveTriangle: [[spoiler:Masami likes Kosuke, who likes Mayumi (who is completely clueless to Kosuke's affections.]]
* ManipulativeBastard: [[spoiler:Nabu/Mr. Kawahara.]]
* MatrixRainingCode: Heavily featured in the OP. In the original PS2 version, it was colored green, but in the PC version, it was recolored blue.
* MaybeEverAfter
** In route B' [[spoiler:Ereshkigal is finally out of her tank]] and Nergal proposes to her in a way. She doesn't say no outright, but she definitely doesn't say yes.
** In the same ending, [[spoiler:Hinata was unable to find Sakuya]] and Yumi was encouraged by her [[spoiler:now doubly deceased friends]] to not wait as long as they did. The story ends with her reaching out a hand to him while the history page in the extra section notes that they began traveling the same path together.
* MayDecemberRomance- [[spoiler:Mutsuki fell in love with Enlil when she was only ''12 years old''.]]
* MeaningfulEcho- [[spoiler:When Hinata and Mayumi meet for the first time, Mayumi's fallen to the ground via a CrashIntoHello, and Hinata reaches his hand out to her (which she responds to with bewilderment). In the ending of Route B', when Hinata is sitting on the ground, depressed about his failure to rescue Sakuya and the permanent loss of his father and "HE", Mayumi comes over to him and reaches her hand out to him in the same way, with him giving a bewildered stare.]]
* MeaningfulName- Several, some of them Lampshaded in-story, while others come from WordOfGod:
** When reversed, the kanji in Hinata Aoi's name forms the kanji for "sunflower". By itself, the name invokes the sun.
** The kanji in Mutsuki's name literally mean "dreaming moon". Opposing Hinata, her name of course deals with the moon.
** If you take out the middle kanji in both Mayumi and Masami's names, you get the kanji for "truth". This is explicitly pointed out by Ishtar at one point.
** Isaiah Nagy (the first IC and [[spoiler:the source of "HE"]]) and Izawa Nami ([[spoiler:Ereshkigal]]) both have similar roots: Cut out the 'iah' from the first name and the 'wa' from the second and you have Izanagi and Izanami, the creation gods of Japanese myth.
* MesopotamianMythology- A major theme in the game, with characters, locations, and terms being named after Babylonian and Assyrian mythological terms.
* MindScrew: There's time travel and a lengthy section where people are in a dream in a dream in a dream and eventually just figure that where they are now is real enough. Several characters speak in exactly the same way [[spoiler:and out of the same body]] making it hard to tell who is even involved in a scene. The story might go from the future to the past. There's some weird relation between Sakuya and Mutsumi, but the story never explains what.
* MiserAdvisor: Nergal only cares about money and only joined the Anunnaki to make more. [[spoiler:Though as a member of the group he fell in love with Ereshkigal, who may one day return his feelings. Either way, for her sake alone he'll waive fees.]]
* {{Mooks}}: The Codebreakers tend to get mowed down. However, they're also quite capable of killing people, as several characters find out.
* MoralityPet: We don’t find out about her for a very long time, [[spoiler:but Andras]] has a cute little sister who is worried sick about him. The rest of his family doesn’t care about him, but since she still does he actually acts something like a decent person around her. Further, he can tell her and nobody else that [[spoiler:he genuinely believes in what Code is doing and has become a person with an actual person, not just a creepy stalker.]]
* MultipleEndings: There are four endings, sort of.
** The BadFuture where [[spoiler:Nabu ends up more or less destroying humanity, kinda]], though this is undone. [[spoiler:Mutsuki’s survival makes this future impossible. Apparently.]] Not really an ending, just considered a possible result of this whole mixup in the history section.
** Route A’ ends with [[spoiler:Hinata tracking down Sakuya and hooking up with her. [[ShaggyDogStory Mutsumi vanishes, most likely never to be seen again]].]]
** Route B’ ends with [[spoiler:Sakuya undiscovered, but Hinata hooks up with Yumi instead. Exarch is defeated when the quantum computers are hooked together and given free reign, at which point they materialize the Nulls. However, since this would result in assimilation due to the computers not understanding human values, they have to be shut off and they take the Nulls with them. He is gone as well and there’s some ship tease between Nergal and Ereshkigal.]]
** In E’… stuff happens. Everyone is there and alive, but in what way is hard to tell. It’s also hard to tell what anyone is actually going to do from here. Or if this is real.
* MysticalPregnancy: Some time ago, a virgin mysteriously got pregnant and gave birth to a girl that was named Akatsuki Akari. [[spoiler:Ishtar has nearly forgotten that this is her own name.]] Hinata runs into another such girl in the infirmary without realizing it. [[spoiler:Sakuya is a third example.]]
* NotHerself
** Ishtar in route C doesn't act quite the same as usual and for some reason Mika is very angry at her. [[spoiler:It's actually Mayumi pretending to be Ishtar so much that she convinces herself that she ''is'' her. Mika is angry because she knows it's Yumi. Plus, she's working with Code and Andras and imitating the person Mika loves, though Mika doesn't realize that Yumi's eye was shot out and replaced rather than just being a contact.]]
** Ea used to be perhaps the kindest and most well grounded of Anunnaki, so her current nearly emotionless state has Ishtar puzzled. Turns out Enlil assassinated her around a year ago, so this is just her Null.
* NotSoDifferent- [[spoiler:It turns out that both eXarch and Code have the same goal- to create a future for Imaginary Children. It just so happens that eXarch wants to use them for their own benefit.]]
* NiceJobBreakingItHero: When [[spoiler:"HE" is summoned by Mayumi in order to save Criminal]] at the end of Route B, [[spoiler:he seals the shutters and pours gas into the room to kill the remaining members of Code... only to end up accidentally killing Ishtar and Masami in the process.]]
* NotQuiteDead: [[spoiler:Ishtar and most of Criminal are killed at the end of Route B, but they all uploaded themselves to the Net and live on as Shadow Nulls. Even Kosuke, who lacks a biocomputer.]]
* ObliviouslyEvil: Marduk and Ashur don't get human values so they can go from very helpful one moment to [[spoiler:risking the extinction of mankind as a physical species]] the next. To them, the real world is meaningless and most of the people they've met are all [=ICs=], who would all do fine [[spoiler:in a world composed merely of data.]]
* ObliviousToLove
** Hinata at first seems incredibly dense for not noticing Sakuya's feelings, but before route A ends he admits that he knows how she feels. he simply can't cope with it in his current state. Plus, it's kind of annoying sometimes.
** Yumi is completely unaware of how Kosuke feels about her because she's never thought about the world in terms of love before. Even after Ishtar tries some well intentioned prodding she just doesn't get it. She doesn't understand how she feels about Hinata, either.
* OlderThanTheyLook: [[spoiler:Sakuya isn’t fifteen, she’s only ten. The original Sakuya made it to age five before dying and getting replaced by this Sakuya.]]
* OneeSama: Ishtar worships her big sister figure, who turns out to be Ereshkigal and one of the Anunnaki. [[spoiler:Yumi, on the other hand, uses Ishtar herself as the OneeSama when pretending to be her. She actually likes Ishtar more than her real sister, though she loves them both.]]
* OneSteveLimit: Subverted, [[spoiler:there are two "Sin"s in Babylon: the original one, Mutsuki, and the new Sin, who is a drug dealer and a member of "Code" (it's eventually revealed that "Sin" is a title given to the commanding officer of [=DlroW=]). The latter ends gets killed by Enlil in the real world for disgracing Mutsuki's name and for abusing his power. Furthermore, Andras becomes the next Sin.]]
* OrWasItADream: Or was it reality? In Route E, it's never quite clear where one begins and the other ends. Eventually, the protagonists just have to say 'Good enough, we'll never know for sure' and move on.
* PerspectiveFlip
** Route’s C and D tell approximately the same story, but from the perspective of Ishtar and He respectively. [[spoiler:Or rather, from the perspective of Yumi and Hinata as they travel back through time step by step.]]
** B’ shows how [[spoiler:Ishtar became a Shadow Null and helped Mayumi become Inanna.]] It’s not quite how things worked originally, but it does show the basic setup. [[spoiler:minus all the time travel shenanigans.]]
* PetTheDog- The Drama CD "Damsel Overbrowse" is this for Masami, [[spoiler:who, being the only one who learns that Mayumi's best friend Kaori has committed suicide, pretends to be Kaori for Mayumi rather than break the truth to her.]]
* PietaPlagiarism: "HE" at the start of Route C and D, holding [[spoiler:Mutsuki's body]] in his arms.
* PoweredByAForsakenChild: [[spoiler:The Enigma system needs to be tied to a "dreaming" human by putting them to sleep and letting their mind create the system. With it, it's possible for Babylon to create sapient Shadows and Nulls. She's taken out when Enlil and Hinata realize the life support on the pod containing her is failing.]]
* PlayfulHacker- Many, but especially Ishtar, who one time manages to make a program to delete viruses like a shooting mini-game.
* PoorCommunicationKills: A good deal of the plot could have been avoided if [[spoiler:Enlil had just put her pride aside and had been willing to listen to others. She also wouldn't have ended up killing several of her friends.]]
* PullingTheThread: [[spoiler:When going through multiple loops of a dream inside a dream, Hinata and Ishtar (or maybe it’s Yumi) finally find the password, but they can’t remember how that happened and when they look at the clock not a minute has passed despite the almost infinite loops they’ve gone through.]]
* PutOnABus- After the end of Route A [[spoiler:and her brief appearance in Route B, Sakuya]] just disappears from the plot altogether. [[spoiler:She eventually reappears in Route A'.]]
* TheQuietOne: He barely speaks. He doesn’t have a single line until the end of Route C and only speaks on very rare occasions in the route he narrates himself. During route E he finally becomes more talkative.
* RapunzelHair- Ishtar. [[spoiler:Ereshkigal's hair is even longer.]]
* RealityEnsues: [[spoiler:A ragtag bunch of misfit hackers with no experience go up against a terrorist organization that greatly outnumbers them. After some brief success, they all get killed apart from one girl.]]
* RefusalOfTheCall- [[spoiler:In one of Route B's Bad Endings, Ishtar refuses to stop "Code"'s assault on eXarch, and instead has Criminal run away to a remote island. Unfortunately for them, TheCallKnowsWhereYouLive...]]
* RescueRomance: Mika is clearly in love with Ishtar after the latter saves her from the stalker Andras. It's not really clear if Ishtar entirely understands that, but she still considers Mika closer to her than anyone in her life apart from her OneeSama.
* RoaringRampageOfRevenge: He goes absolutely berserk on Code in route D [[spoiler:but the thing is, he's going berserk for something that actually hasn't happened yet. Mutsuki will die in April of 2033 but the story skips back over a period of months until it's October of 2032. If he kills Enlil while on his rampage, then Mutsuki's death is assured.]]
* RoboticReveal- [[spoiler:"HE" in Route C is revealed to have a mechanical left arm.]]
* SacrificialLion- [[spoiler:Mika in Route B.]]
* SatelliteCharacter: Flauros only really exists to show Andras’ good side. She does pass some information along, but given that scenes with Flauros are just bonus scenes the story obviously worked fine without a source for that information.
* SatelliteLoveInterest: She’s not undeveloped as such, but Sakuya’s role is basically to be Hinata’s potential girlfriend, though not much really comes of it. [[spoiler:She’s somewhat more important in A’ but even then the role is largely focused on Hinata’s love life. Namely, she was injected with a virus intended to repair Hinata’s defective Y chromosome and allow him to reproduce.]]
* TheSchlubPubSeductionDeduction
** Attempted by Ishtar to get some information out of Nergal. It fails miserably because he considers her just a kid. One with no sex appeal at that.
** Amusingly, in Route E [[spoiler:Yumi of all people]] pulls it off against Andras successfully. [[spoiler:While in the form of Ishtar, no less.]]
* SecondLove
** When Yumi begins to suspect she might like Hinata, she muses it wouldn’t the first time she’s felt that way. She thinks of Ishtar as [[spoiler:her OneeSama]] for a reason.
** Hinata himself [[spoiler:loved Sakuya first]] but the ending of B’ implies he’ll eventually [[spoiler:get together with Yumi.]]
* SelectiveObliviousness: Hinata knows how Sakuya feels, but he’s trying not to think about it.
* ShaggyDogStory: In the A’ ending, the world is saved and whatnot [[spoiler:but Mutsumi is gone again. So much for all that work.]]
* ShrinkingViolet: Mayumi at first seems very meek and shy, but it actually doesn't really influence her behavior that much apart from making her polite and friendly. She does have little faith in herself, though, and as a result is extremely happy when Hinata is genuinely complimentary regarding her abilities. Masami in particular constantly makes her feel inferior.
* ShoutOut- Several to various pieces of literature, such as Literature/AliceInWonderland, The Once and Future King, Theatre/{{Macbeth}}, Literature/TheEpicOfGilgamesh, Literature/AConnecticutYankeeInKingArthursCourt, [[Film/BladeRunner Do Androids Dream Of Electric Sheep]]... the list goes on.
* SiblingTriangle: Masami likes Kosuke but he likes Mayumi, who in turn likes Hinata. Yumi doesn't really get why Masami and Kosuke are fighting nor how she's personally involved in things.
* SoleSurvivor: The only member [[spoiler:of Criminal]] that makes it out of an Exarch raid [[spoiler:is Mayumi, who begins imitating Ishtar out of respect and self deprecation.]] On the other hand, [[spoiler:they all survive as Nulls.]]
* SoundtrackDissonance- [[http://www.youtube.com/watch?v=D6ZOBInkJL8&feature=related "Subnetwork"]], a rather calm, soothing theme... which often plays as something bad is happening or when people are dying.
* StakingTheLovedOne: In B', Enlil is forced [[spoiler:to personally shut down her daughter Marduk because Marduk and Ashur are incapable of understanding the human view of life and might wipe out humanity.]]
* StalkingIsLove: Izaiah Nagy fell in love with Izawa Nami and tracked her all around the world. He was almost brought in on stalking charges, but she actually felt the same way.
* StalkerWithACrush- Andras to Mika, which traumatizes her horribly. [[spoiler:In one of the Bad Endings, he ends up killing her, while in another, she shoots him dead.]]
* StepfordSmiler: [[spoiler:Ditzy as Mutsuki’s LEM is, even she knows that she’s going to die pretty soon, no matter what happens.]]
* StudentTeacherRomance: Once or twice, it sounds like Yayoi isn't just teasing Hinata when she flirts with him. She also gets embarrassed for real when he says he wants to be someone she can confide in in the future.
* SunglassesAtNight- "HE" always wears sunglasses, regardless of time or place. [[spoiler:When he does take them off, it's to signify that he's fully speaking as Hinata at that moment.]] Justified in that they're meant to protect his eyes from flash grenades.
* SuperPoweredAlterEgo: [[spoiler:This is essentially the relationship between Hinata and "HE": after "HE" is downloaded into Hinata, he can use his body to fight, but both Hinata and "HE" are existing at the same time, and don't require to "shift" or anything. However, Hinata has none of "HE"'s abilities.]]
* SurprisinglyGoodEnglish- With a few exceptions, the written English in the game is correct, both grammatically and spelling-wise.
* SurvivorsGuilt: As the sole survivor of [[spoiler:Criminal, Mayumi]] has to deal with a lot of this [[spoiler:though Ishtar hijacks her old computer to help cheer her up and the character development does stick.]]
* SymbioticPossession
** [[spoiler:After suffocating to death, Ishtar becomes a Shadow Null and eventually joins up with Mayumi, instantly gaining the two of them the leadership of Code.]]
** [[spoiler:He and Hinata, who were already very similar people, wind up sharing a body after Enlil nearly kills Hinata and Hinata cries out for more power.]]
* TalkingToHimself- Twins Mayumi and Masami Shinozuka, who share the same voice actress. [[spoiler:"HE" shares a voice with Hinata, "Ashur", and Isaiah, while Lem shares a voice with Mutsuki "Marduk", and Ereshikigal.]] There are also several other characters in the game who share voice actors, but that's more due to the limited voice cast rather than other reasons.
* TakeUpMySword- [[spoiler:Ishtar to Mayumi at the end of Route B, giving her the rosary that her "Onee-sama" gave to her, as a sign that her role has ended.]]
* TakingTheBullet- [[spoiler:Kosuke dies in Route B after taking a bullet aimed at Mayumi and Masami.]]
** [[spoiler:In Route E, Lem does this for Mayumi (with Ishtar's appearance), taking a bullet aimed for her.]]
* CoolBigSis/ TeamMom- Ishtar for the rest of Criminal.
** [[spoiler:As it turns out, she literally is the former for Mayumi and Masami.]]
* TheTease: Ishtar would like to be able to pull this off, but it seems she just lacks the sex appeal.
* TechnicalPacifist- [[spoiler:During the raid on eXarch in Route B, Kosuke notably selects a tranquilizer gun as his weapon.]]
* ThemeNaming- Many characters, locations, and terms are named after entities from Babylonian/Assyrian mythology, and there are many allusions to said mythologies.
* ThirdPersonPerson- Mayumi.
* ThroughTheEyesOfMadness: He in Route D clearly has no idea what’s going on. Unlike Ishtar from Route C, he’s also unable to figure out that [[spoiler:He’s progressing backwards in time, not forwards. He also fails to realize what any of his relationships actually are.]] Route B’ confirms that the reason [[spoiler:Code reacted to him so strangely is because they considered him an ally.]]
* TimeTravel: Shadow Nulls have no physical form and thus are unbound by time. For some reason.
* TomatoInTheMirror- [[spoiler:Ishtar in Route C is actually Mayumi, who took up Ishtar's role after Route B.]]
** [[spoiler:Also done in Route D, where it reveals that "HE" is actually Hinata, but as this is revealed in Route C and is heavily hinted in the route, it's not as much as a surprise.]]
* TookALevelInBadass: [[spoiler:Hinata and Mayumi, but especially Hinata, who squares multiple levels at once when he becomes "HE".]]
* TragicKeepsake: [[spoiler:After his father's murder, Hinata wears the chronograph that his father once wore.]]
* {{Transgender}}: Enlil hates femininity and is said to have the brain of a man despite having the body of a woman. She’s still always referred to as female by people who know, though, and she doesn’t seem to mind much.
* TrulySingleParent: [[spoiler:Sakuya was originally born as one of the virgin birthes that have begun to appear. However, she died. Nabu remade her from a fabricated strand of DNA, meaning she has a TrulySingleParent twice.]]
* {{Tsundere}}
** Sakuya is an obvious tsundere for Hinata. She constantly gripes at him, but is also so doting that he has to tell her over and over that she's not his mother.
** Masami is also very tsuntsun for Kosuke. It doesn't help that she's genuinely frustrated that he so clearly prefers her 'useless' but more traditionally feminine sister to her. She's also tsundere for Hinata minus the attraction, however, given that she'll rant that he's scum nowhere near good enough for her sister while also requesting that he call her Sami like how he calls Mayumi Yumi. She's even tsundere to her own ''sister'', picking on her frequently and even having a big fight with her only to act protective of Yumi's future despite it going against her own interests regarding Kosuke.
* TwinSwitch- In an additional scene in Route B, [[spoiler:Masami pretends to be Mayumi in order to confess to Kosuke since Kosuke likes Mayumi more. However, Kosuke sees right through her and tells Masami that though he likes her, he doesn't like her in that way.]]
* TwinTelepathy: Twin [=ICs=] use the unused parts of each others’ brains and acquire special genius abilities as a result.
* UngratefulBastard: Nabu promises his eternal devotion of Criminal will come save him [[spoiler:and they all get killed doing it apart from Yumi]] but when they meet again [[spoiler:he just laughs and taunts them about being unable to break through his security quickly enough.]]
* UnreliableNarrator: By a certain point in Route E, it’s no longer possible to say with any certainty that anything being seen is actually real. [[spoiler:The story admits that there’s no way to convincingly prove that the world they’re in at the end is real, but Hinata just figures it doesn’t matter.]]
* UnrequitedLove: Nergal was in love with Ereshkigal, but she was in love with [[spoiler:Izaiah Nagy.]] To pursue him, [[spoiler:she entered a pod like Mutsuki’s located in Nergal’s shop after ‘marrying’ him. When He finally moves on at the end of B’, Nergal awkwardly asks if she wants the marriage to be the real thing and she says she’ll think about it.]]
* VirtualGhost- Shadow Nulls, who are essentially the remainders of someone who used {{Cyberspace}} frequently, and can continue to live after death in that world, but cannot interact with the real world unless they have someone living to do it through.
* WhatHappenedToTheMouse: Sakuya is one of the most important characters in A route and appears briefly in B, but goes unmentioned in C or D and is mentioned only in passing in E and C’. The only route where she appears again, A', doesn't even bother to bring up the reason everyone was so desperately looking for her.
* WhatTheHellHero
** Magdalene in Ishtar’s C route is pissed at Ishtar [[spoiler:for pretending to be Ishtar when she’s actually Yumi. She’s even angrier when she briefly acts just like Ishtar and calls her Mika-chan, causing her guard to slip and allowing Yumi to take back the Exabyte containing Masami.]]
** She’s similarly furious to see [[spoiler:Yumi working with Andras, completely uncaring that she’s just manipulating him for information.]]
* WhereAreTheyNowEpilogue: Route E's epilogue shows Hinata, Mayumi, and Mutsuki one year after the end of the game. However, the story actually continues from there into two different endings. Three if you count E'.
* WildCard: Ea tends to get in the way frequently, but it's never made clear as to exactly why she's getting in the way. She also helps on a few occasions before getting back in the way again.
* {{Yandere}}: Enlil is obsessive when it comes to Mutsuki [[spoiler:and murders several friends to 'protect' her]] as well as trying to kill Hinata for making her feel isolated years ago.
* YourMindMakesItReal- Specifically averted, though people with biocomputers can have their biocomputers potentially short, or at the very worst, fry their brain.
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