12Riven is the first and only game in the ''Integral'' series, based off of the popular ''Infinity'' series, made up of {{Never7}}, {{Ever17}}, and {{Remember11}}. Like most of the games in the Infinity series, the game has two protagonists.

On May 20th, 2012, Renmaru Miyabidou (an OrdinaryHighSchoolStudent) receives a text from an unknown sender telling him that his childhood friend Myuu Takae will be murdered on the roof of a hotel. At the same time, Narumi Mishima, a cop, receives a similar text from her friend and co-worker Makoto, which also tells her to find Renmaru, as he is an ally. Renmaru arrives at the scene first, where he finds Myuu and a boy named [[GenderBlenderName Mei Kiridera]], the leader of an organization called Psi-Climinal (an organization made up with those with the power of [[PsychicPowers Psi]]), who intends to kill Myuu, as she is an interference to their plan, "The Second Eclipse Plan". Narumi soon arrives, and as things go downhill real fast, both protagonists split up in opposite directions, both which will lead them to opposing Psi-Climinal.

This VisualNovel is noted for having a troubled production history- while it was being written, KID went bankrupt, and so production was halted until Cyberfront picked it up. It was originally supposed to be the first game in a trilogy, but poor reviews and sales killed chances of that.

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This game provides examples of:
* ArcNumber: 12.
* AndIMustScream- [[spoiler:Anyone with Eclipse Syndrome.]]
* [[spoiler:AssimilationPlot]]- [[spoiler:The goal of The Second Eclipse Plan is to use radio waves all around the world to give everyone Eclipse Syndrome.]]
* BigBad [[spoiler:Liminality. The closest thing they have to a physical BigBad is Omega.]]
* BittersweetEnding- [[spoiler:Narumi's Route. The Second Eclipse Plan has been stopped, but Makoto and "Chisato" are dead, and Narumi is left with many questions she knows she'll never get answers to.]]
* {{Bowdlerization}}- In the PS2 release of the game, shots of a character bleeding had their colors inverted to censor the blood (though shots of smaller bloodstains were left alone). This was changed in the PSP version, as the originals were shown normally, and was partially averted in the PC version.
** Furthermore, in the PS2/PSP versions, there was a scene cut where it showed Myuu as a kid getting bullied by other kids (and Renmaru also getting bullied). The scene was cut to get a B (12+) rating, but the scene was put back in the PC version.
** In the trial version of the game, when Kiridera kicked Chisato in the stomach, she coughed up blood. This was removed in the final version and never restored to any later versions.
* BroughtDownToNormal- Psi users in World A, who not only can't use their powers, but can only remain there for 12 minutes[[spoiler:, with the exception of Myuu and Kiridera, thanks to the CODECS]].
* ChekhovsGun- ''Way'' too many to count.
* CloningBlues- [[spoiler:While Chisato isn't exactly a clone, she was the closest of the 24 Psi Clones to resemble Myuu, leading to her being experimented on. As a result, she resented Myuu (combined with DontYouDarePityMe) until Myuu and Mei saved her from being vivisected.]]
* CreepyMonotone- Those with Eclipse Syndrome tend to talk like this. [[spoiler:In another example, when Tango's true identity as Omega is revealed, his voice shifts from innocent sounding to a cold, emotionless monotone.]]
* {{Determinator}}- Both protagonists, but especially Renmaru.
* [[spoiler:DressingAsTheEnemy]] [[spoiler:Renmaru does this in order to gain access to the school where Myuu and Maina are being held captive, where he receives help from Chisato, who hacks the school's database so that the data makes it seem like he's Omega, Chisato's "brother".]]
* DownerEnding- [[spoiler:Renmaru's Route. No matter what, either Myuu gets shot and killed by Makoto, or she gets kidnapped by Kiridera. Either way, it's a lose-lose situation for Renmaru, who remains trapped in World A. Worst of all, The Second Eclipse Project is a success, and it's heavily implied that the rest of the world kills each other off due to the lack of natural resources in World A.]]
* [[spoiler:EveryoneIsRelated]]
* ExpositionBreak- Very frequent (and a common complaint about the game).
* GondorCallsForAid- [[spoiler:In the final battle in World A with Psych-Liminal, the Mirage Kingdom and the Shimura Club appear to fight off the {{Mooks}} while Renmaru heads for the top floor of Integral Tower.]]
* [[spoiler:GoodAllAlong]]- [[spoiler:Kiridera.]]
* [[spoiler:HalfIdenticalTwins]]- Averted. [[spoiler:Myuu and Mei barely look alike at all.]]
* HappilyAdopted- [[spoiler:Narumi, who gets along well with her adopted father (Boss), despite all their teasing.]]
* HealingFactor- Some people with Psi have this, though it's not perfect.
* HeelFaceTurn- [[spoiler:Makoto in the Integral Route, though it doesn't last for long, as she's quickly [[HeelFaceDoorSlam killed afterwards]].]]
* HotBlooded- Renmaru.
* LaserGuidedAmnesia- Omega. [[spoiler:It's implied in the Integral Route that he was faking it all along as a means to throw people off.]]
* LesYay- Makoto ''definitely'' thinks of Narumi as more than a friend.
* LongLostRelative- [[spoiler:Narumi is actually Myuu and Mei's older sister (though only Mei knew this).]]
* LongSongShortScene - "Eclipse", a nice, five minute song that only plays twice in the game (one of those times being optional), where you'll only hear about 30-60 seconds of it (unless you wait it out).
* MeaningfulName- Several:
** [[spoiler:Myuu (海) and Mei's (鳴) names are spelled with the same kanji as their older sister, Narumi's (鳴海), because if she didn't type the NRM 66 retrovirus code, they would never have been born.]]
** [[spoiler:Chisato was named by Myuu, after the flowers she would constantly look at in the garden in the research facility where the two were kept.]]
** Narumi's name comes from an anagram of "liminal" (Nallmii). When pronounced in Japanese, it comes out as "Narumi".
* {{Megane}}- Omega. [[spoiler:As it turns out, he is actually Renmaru, who normally wears contacts, but switches to glasses after he has to take his contacts out at one point. By the Epilogue, he's decided to stick to wearing glasses.]]
* Meganekko- Maina.
* MobWar- Though neither of them are exactly crime syndicates, the conflict between the Mirage Kingdom and the Shimura Club in World A is essentially this.
* TheMole- In her audio message to Narumi, Makoto tells her that there's a mole in Public Security 12. [[spoiler:However, [[ExactWords what she never says is that she herself was the mole.]]]]
* MrExposition- Maina, Maina, Maina.
* MythologyGag- Yuyu apparently goes to [[{{Ever17}} Kyumeikan]] [[{{Remember11}} University]] as well, as she's wearing the same uniform that [[{{Ever17}} Sara]] does.
* NamesToKnowInAnime
** Creator/AiNonaka - Myuu.
** Creator/AkioOhtsuka - Boss.
** Creator/JunichiSuwabe- Ohtemachi.
** MasayaMatsukaze- Kiridera.
** NaozumiTakahashi- Omega.
** Creator/RinaSato- Maina.
** YuuKobayashi- Yuyu.
* NoPronunciationGuide - [[spoiler:The subtitle is supposed to be pronounced "psych liminal" but it gets confusing when "psy" is substituted with the Greek letter "psi".]]
** [[spoiler:That's because the subtitle is read in Japanese as "saikuriminaru", which is meant to be read as both "Psi Criminal" and "Psych Liminal".]]
* ObfuscatingStupidity- [[spoiler:Maina knows almost everything about what's really going on, but keeps it to herself.]]
* OffModel- One of the biggest complaints of the game were that many of the CGs looked like this when compared to the character models. Most of those CGs were redrawn in the PSP re-release to fix this, but some still look off.
* OrdinaryHighSchoolStudent- Renmaru.
* PhotographicMemory- Exists as an actual condition: CycloPedia Syndrome (CPS). Narumi has this, [[spoiler:as does Maina.]]
* ThePowerOfLove- Renmaru's love for Myuu is [[{{Determinator}} what keeps him going]], no matter how bad the situation.
* PsychicPowers- Psi. [[spoiler:However, this is mostly an optical illusion, as Psi allows its users to jump to World A, where they can perform normal actions that will look like "psychic powers" in the real world.]]
* RedHerring- [[spoiler:The game sets up many hints that Ohtemachi is the new leader of the Shimura Club, only for it to be revealed at the end that the actual leader is Maina (who is dating Ohtemachi).]]
* [[spoiler:ReverseMole]]- [[spoiler:Kiridera, though played with in that he's not working with any one team, but for his own intentions.]]
* SequelHook- One that was never resolved due to the ''Integral'' series being cancelled.
* ShoutOut- A character named "Boss" voiced by AkioOhtsuka...[[Franchise/MetalGear sound familiar?]]
** Each route takes place over the course of [[Series/TwentyFour 24 hours]] (WordOfGod admits this aspect was inspired by Series/TwentyFour).
* StableTimeLoop- [[spoiler:Kiridera and Renmaru set one up in the Epilogue, ensuring that the events of the game and everything leading up to it occur.]]
* TalkingToHimself- [[spoiler:Shinkuro to Ohtemachi, Maina to Narumi, and Omega to Renmaru (though the latter two are only heard in flashbacks initially.]]
* ThemeNaming: [[spoiler:The 24 Psi Clones were all named after a different letter in the Greek alphabet.]]
* {{Tsundere}}- Myuu.
* {{Tykebomb}}- All the members of Psi-Climinal count, as they're all under the age of 18. [[spoiler:This is best personified in the true Omega, who, once his cover is blown, is revealed to be a cold-blooded killer with no remorse.]]
* [[spoiler:VictoriousChildhoodFriend: Myuu.]]
* WhiteHairBlackHeart- Kiridera. [[spoiler:However, this is subverted in the True Ending.]]
* YouGottaHaveBlueHair- Chisato. [[spoiler:As it turns out, Myuu's real hair color is blue as well. This is justified, as those with the NRM 66 retrovirus are noted to have strange hair and skin pigmentation.]]
* YouHaveFailedMe- [[spoiler:Makoto was assaulted, then later murdered, by Omega, as punishment for failing to carry out her job to eliminate Myuu in World A.]]
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