[[quoteright:350:http://static.tvtropes.org/pmwiki/pub/images/ShinMazinZero_3937.jpg]]
[[caption-width-right:350:A God saves the world... Or a devil will destroy it?]]

->''Rage. Pain. Sorrow. Every emotion. Everything coming together. Flowing to the same place... To the Demon God of Demise. Inside every wish becoming zero. At my wit's end, I can just watch.''

''Shin Mazinger Zero'' (真マジンガーZERO) is a manga written by Yoshiaki Tabata and illustrated by Yuuki Yugo (the team behind ''[[Manga/WolfGuyWolfenCrest Wolf Guy]]'' and ''Manga/{{Akumetsu}}''), part of the ''Anime/MazingerZ'' SuperRobot CashCowFranchise. It debuted in 2009 at nearly the same time as the anime ''[[Anime/ShinMazinger Shin Mazinger Shougeki! Z-Hen]]''. Despite the similar titles, they are unrelated re-imaginings of the original 1972 ''Anime/MazingerZ'' manga/anime by Creator/GoNagai.

Kouji Kabuto is an OrdinaryHighSchoolStudent. He has a beautiful girlfriend, he rides a bike, he has a certain {{Delinquent}} air, and the only unusual thing about him is his father and grandfather are world-renowned scientists. However, one day he starts having horrible nightmares that feel scarily real -- nightmares where the world has been burnt to ashes by a [[HumongousMecha huge, robotic, god-like devil]] named Mazinger Z, and a pretty but not-quite-human-looking lady offers him the chance to save the world... and then she kills him.

After one of these nightmares, he and his girlfriend Sayaka are summoned to Sayaka's father's workplace, the Photon Power Laboratory, to assist with an emergency. In short order, Kouji loses his father, his girlfriend, his grandfather and an arm, and his body gets absorbed by the mechanical devil he saw in his dreams. As he crosses the DespairEventHorizon with the subtlety of a bull in a china shop, a group of unknown [[{{Robeast}} giant mechanical monsters]] attack. Filled with berserker rage, his sanity slipping, Kouji goes to fight them... Ultimately, his nightmare comes true -- he defeats the monsters, but the world is destroyed, and his body is almost completely consumed by Mazinger Z. Then the same not-quite-human lady appears to him, tells him to save the world, and kills him. [[GroundhogDayLoop Wait, again?!]]

Kouji wakes up and to his surprise he is whole and healthy, piloting Mazinger Z in the middle of a battle -- and Sayaka is alive and in her own robot. Later, a new transfer student joins his class, and Kouji feels like he's seen her before...

It ended in 2012 after ten volumes, and is continued in ''Shin Mazinger Zero vs the Great General of Darkness'' (''Shin Mazinger ZERO vs Ankoku Daishogun''), introducing characters and concepts from ''Anime/GreatMazinger''.

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!! This manga provides examples of:
* ArcWords: Remember when Kabuto's gramps says that Mazinger Z has the power to become a demon and destroy the world? he wasn't kidding.
* AscendedExtra: Minerva X appeared in only one episode of the anime, here she's a major character.
* AfterTheEnd: The manga ''starts'' this way.
* ApocalypseHow: DYNAMIC FIRE!
* BadFuture: Minerva X sends Kouji back in time to stop one from happening. Again and again.
* BadassGrandpa: The BigBad Dr. Hell is surprisingly, improbably ''huge and ripped'' for a 70-year-old. And besides watching from his base like he does all the time, he attacks the ''White House'' in person.
* BerserkButton: Hurting or trying to hurt Sayaka in front of Kouji is not the last thing you want to do. It is the last thing you ''will ever'' do.
** Dr. Hell does not take it kindly when his underlings make him look ridiculous, either.
* ActionPrologue: The first chapter appears to be this, then the story resets again after the fourth chapter. The main story starts with chapter five.
* BreatherEpisode: After two ''very'' {{grimdark}} timelines the chapters of the main timeline are lighter and comedic. [[CerebusRollercoaster Until things get dark again!]]
* BrokenBird: Minerva X. She's gone through 2,798 cycles of time, witnessing the events where Mazinger becomes a demon in all of them, what can you expect?
* BlueAndOrangeMorality: Minerva X. Despite (or maybe ''[[MindScrew because]]'') she was created by humans, several of her personality traits - mainly her conception of what love is - are completely bizarre. Because she was created to be Mazinger's partner in battle, [[CargoShip she is in love with Mazinger]] in spite of she knows it is a machine and it is not sentient. She also treats the pilot of a HumongousMecha like if it was another part of the mecha (presumably, the brain). Thus, she teases Sayaka because she saw Aphrodite (Sayaka's FemBot) fighting alongside Mazinger and got jealous, got... [[TheImmodestOrgasm all bothered]] when she was inside Mazinger's cockpit, and she told her she loved Kouji... but she loved Kouji piloting the Hover Pilder even more, and above all she loved Kouji on the Pilder piloting Mazinger. [[http://www.mangareader.net/930-43892-28/shin-mazinger-zero/chapter-8.html Usually Kouji and Sayaka only shake their heads and accept her as she is]].
** Minerva's love makes some sense when you remember that she's [[spoiler: the reincarnation of the same Minerva from the anime that fell in love with that continuity's Mazinger]]. Of course she would love Kouji especially when he pilots Mazinger because [[spoiler: she's in love with it]] and without its pilot, Mazinger is practically lifeless.
* CallBack: Tons of the flashbacks, which are important to the plot.
* ClingyJealousGirl: Sayaka. Even more than in the original series. Get her jealous and angry enough, and she is able to tear three Mechanical Beasts apart. At once.
* CombatTentacles: Professor Juuzo Kabuto in the first arc/second timeline.
* CompositeCharacter: The Demon Mazinger Z is a combination of classic Mazinger Z with Anime/{{Mazinkaiser}}.
* DarkerAndEdgier: Might or might not be for every other Mazinger continuity. And HOW!
* DespairEventHorizon: Kouji Kabuto in the first two timelines [[spoiler:or rather 2,797th and 2,798th]].
* DownerEnding: This manga as a whole serves as one for the original anime and manga continuity.
* DyingDeclarationOfLove: In the first arc Sayaka tells Kouji she loves him as she dies [[spoiler:gruesomely]]. It was especially heartbreaking because in that timeline they had managed to go past [[WillTheyOrWontThey the typical]] [[CantSpitItOut status quo]] [[UnresolvedSexualTension in their]] [[BelligerentSexualTension relationship]], as usually depicted.
* EldritchAbomination: Apparently, Mazinger Z itself has potential to become one.
* FanService: It's based on stuff by Creator/GoNagai, what can you expect? Especially (and constantly) true with Minerva X.
* FanDisservice: Sayaka's death in the second timeline: [[spoiler:she's stripped, tentacle-raped and impaled.]]
* FlatWhat: Kouji explains that Minerva X is not human but is actually a Super Robot created by Juuzo Kabuto to be Mazinger Z's partner. Sayaka has this reaction... also because Kouji and Minerva X are in Mazinger's cockpit [[NotWhatItLooksLike with their faces in each other's crotches.]]
* FreakinessShame: After Kouji finishes utterly ''trashing'' a ten-foot robot with his bare hands in front of his girlfriend Sayaka, he freaks out and asks her [[IAmAMonster if she was as terrified of that sudden show of inhuman ability as he was]]. [[http://static.tvtropes.org/pmwiki/pub/images/Shin_Mazinger_Zero_C01_34img.jpg Sayaka's response]] can be summed up as, "Hell no! That was both completely awesome ''and'' hot."
* FromBadToWorse: In this [[http://i14.mangareader.net/shin-mazinger-zero/2/shin-mazinger-zero-931276.jpg picture]], Kouji is dashing headfirst into the DespairEventHorizon after [[spoiler:his father has been murdered,]] [[spoiler:his girlfriend has been tentacle-raped and murdered]], and [[spoiler:he has been forced to kill his MadScientist of a grandfather, losing an arm in the process]]. It gets worse? Oh, yeah. Straightaway, an EldritchAbomination dwelling in the body of a HumongousMecha will possess his body and will use him to fight an army of {{Robeast}}s. During three months he will relentlessly fight Dr. Hell's Mechanical Beast army, gradually losing his sanity as the whole world falls into ruins. Finally his mind will snap, and the EldritchAbomination - fueled by his negative emotions of rage, despair, madness, grief and pain - will go berserk [[EndOfTheWorldAsWeKnowIt and burn the world to ashes]]. The funny part? That is the ''first'' story arc.
* FunWithAcronyms: '''M'''ultidimensional '''A'''utomaton '''Z'''illion '''I'''nfinity '''N'''eural '''G'''enerative '''E'''xterminate '''R'''everter. Surprisingly, ItMakesSenseInContext.
* GrievousHarmWithABody: In the first story arc Kouji has his arm ripped off. He picks it up and uses it like a RocketPunch. (After all, he's the TropeNamer!)
* GroinAttack: Dr. Hell walks into the White House and takes the President of the United States hostage by squeezing his balls. And lifts him above his head!
* GroundhogPeggySue: The premise: GroundhogDayLoop + PeggySue story, to SetRightWhatOnceWentWrong. Except it has gone wrong again and again.
* GutPunch: The ''first'' arc alone has multiple.
* HopeIsScary: Minerva X has failed 2,798 times in averting the EndOfTheWorldAsWeKnowIt. She does as much as stating all of those times she hoped, and her hope was in vain. However, in the current timeline she is stuck in, she is seeing signs that maybe things will finally be different this time around. So she feels a glimmer of hope... and she is afraid of being hopeful only for getting disappointed and heart-broken again.
* HopeSpot: An especially cruel one. [[GroundhogPeggySue After failing nearly three thousand times]], the heroes manage to save their timeline. The epilogue show them living peaceful, happy lives... but then [[spoiler:Prof. Morimori makes a terrifying discovery before being murdered by Archduke Gorgon,]] and the last page advertises the sequel: ''Shin Mazinger Zero vs Ankoku Daishogun''. Any remotely familiar with the Mazinger mythos knows the Earth is going to be a CrapsackWorld very, ''very'' quickly, and Mazinger Z is [[spoiler:going to be destroyed,]] making Kouji's triumph over Dr. Hell useless and meaningless.
** But then, enter [[spoiler:Tetsuya and Great Mazinger!]]
* HotBlooded: maybe even more than the original! In Chapter 6 & 7, Sayaka of all people becomes this after hearing some sexual innuendo.
* HotBloodedSideburns: Kouji's ones are even larger than his original incarnation's sideburns. It fits because he is even ''more'' hot-blooded.
* HumanPincushion: In chapter two [[spoiler:Sayaka]] died when [[spoiler:her]] body was impaled by several dozens of iron rods.
* HumongousMecha: Take a guess.
* TheImmodestOrgasm: Minerva X's reaction while the Pilder docked with Mazinger Z. While she was straddling Kouji, which was awkward for him.
* ImpaledWithExtremePrejudice:
** In one of the first chapters [[spoiler:Sayaka was impaled by several huge, metallic rods.]]
** Later, Toros D7 tries to impale Mazinger and Aphrodite.
** Still later, [[spoiler:Kouji is impaled with the Bardos Wand by Dr. Hell.]]
* InnocentInnuendo: Minerva X boards the Hover Pilder and sits on Kouji's lap facing him, much to his embarassment and Sayaka's chagrin.
* LaughingMad: [[spoiler:again, the 2798th cycle version of Kouji Kabuto.]]
* InsertSong: The first theme song of the ''Anime/ShinMazinger'' anime, ''Kanjite Knight'', "plays" during the first time the timeline resets.
* TheMole: The Gamia Q sisters infiltrated into Kouji's school to murder him.
** ReverseMole: Similar to the original series, Minerva X was designed as a partner for Mazinger Z by Juuzo Kabuto but the plans and materials were stolen by Dr. Hell. He built Minerva X believing she would work for him, but in reality she was always on the heroes' side and was only biding her time before defecting the first chance she got.
* MyHeroZero: ''Awfully'' subverted. Mazinger Z of ''Shin Mazinger Zero'' is an EldritchAbomination.
* MysticalWhiteHair: Minerva X.
* MythologyGag:
** The Gamia Q sisters end up just like the original manga. [[spoiler:one is killed by friendly fire, one is cut in half vertically and one is cut in half at the waist.]]
** At some point Sayaka switches to a ''[[{{Stripperific}} lewd]]'' bondage-themed pilot "suit" first seen in ''[=MazinSaga=]''.
** Kouji eventually [[spoiler:becomes a cyborg]] similar to the ''Mazinger Z'' manga by Gosaku Ota - [[spoiler:(using the same technology as [[Anime/CuteyHoney Cutey Honey's]])]].
* NewTransferStudent: Dr. Hell sends Minerva X to Kouji's school so she can kill him. However, Baron Ashura sends Gamia Q on the same pretense, in order to please Dr. Hell after losing face.
* NotWhatItLooksLike: Kouji and Minerva X are together inside Mazinger Z's cockpit during a battle. After Mazinger is knocked down, Minerva ends up upside down on Kouji with their faces in each other's crotches. Sayaka, who has just destroyed three Mechanical Beasts in a fit of jealous rage, sees them in the cockpit. They try to explain, but Sayaka tries to murder them anyway.
* OffingTheOffspring: [[spoiler: Juuzo does this to his son Kenzo. He then tries to do the same to his grandson, Kouji, and kills Sayaka just in case Kouji has impregnated her. He really wants the Kabuto line out of the way.]]
* OhCrap: Kouji and Minerva X find themselves in an awkward position in the Pilder and make tremendously alarmed faces when Sayaka sees them.
* PosthumousCharacter: Juuzo Kabuto dies soon after he gives Mazinger Z to Kouji, and this is the case in the original series and the main timeline of the manga. In the first arc however, there are... complications.
* TheProfessor: Lots of them: Juuzo Kabuto, Kenzo Kabuto, Gennosuke Yumi (Sayaka's father), the Three Professors. Even Dr. Hell was one [[MadScientist before he turned evil.]]
* RefusalOfTheCall: Kouji JumpedAtTheCall in the original series. In the first timeline seen, he refused the call and we got to see the outcome. It was not pretty (unless your definition of pretty includes the planet scorched away and the humanity wiped out [[spoiler:by Mazinger Z]]).
* {{Reincarnation}}: Everyone, but most notably Kouji, before the start of the manga. [[spoiler:Minerva X is shown to be one of her ''giant'' robot namesake from the original show.]]
* RidiculouslyHumanRobot [[RobotGirl Girls]]: Minerva X and the Gamia Qs.
* RippleEffectProofMemory: Both Kouji and Minerva have it. However Kouji's memory is faulty, and he only remembers what happened in former timelines through dreams and sudden flashbacks, and they are so vague and so random -and seldom he has them when he needs them- that they are all but useless. On the other hand, Minerva remembers with utter clarity how they failed thousands of times in averting the EndOfTheWorldAsWeKnowIt, and how her beloved, her friends and the whole humanity died several thousands of times because she failed.
* {{Robeast}}: Dr. Hell's Kikaijuu (Mechanical Beasts) and the Mykene Sentoujuu (War Beasts) in the sequel.
* ShipperOnDeck: Minerva X [[http://www.onemanga.com/Shin_Mazinger_Zero/8/30/ ships Kouji/Sayaka]] in spite of being a ClingyJealousGirl.
* ShoutOut:
** Look at [[http://www.mangareader.net/930-37870-5/shin-mazinger-zero/chapter-4.html this page]]. Mazinger goes berserk, its mouthplate splits, the HumongousMecha roars and it chewes a Kikaijuu. Pretty blatant ''Anime/NeonGenesisEvangelion'', would not you say?
** Kouji's school teacher in chapter 5 is a [[TheCameo character of]] ''Harenchi Gakuen'', another Creator/GoNagai series.
** In Chapter 6, Sayaka, after hearing the words "Gan gan gan gan" says that this is not ''Manga/GetterRobo''.
** In Chapter 9, they visit a hot spring. The men's side has a statue of Manga/{{Devilman}} (like the original manga), while the women's side has a statue of Satan.
** [[Anime/CuteyHoney Honey Kisaragi]] appears as an IdolSinger. And later she does transform into Anime/CuteyHoney to help the heroes.
** The President of the United States is [[UsefulNotes/BarackObama black]]... and has the design of Jim Mazinger from ''Manga/ViolenceJack'', where Go Nagai reimagined Mazinger Z as a blind black man.
* StealthSequel: At the beginning it seems an alternate universe or retelling of the original ''Anime/MazingerZ''... and then it is revealed that it is a sequel to the original series, in which the characters are locked in a perpetual time loop.
* StevenUlyssesPerhero: As a transfer student, Minerva X assumes the name "Minerva Ecks".
* TechnoBabble:
** ''Mazinger'' is an acronym for Multidimensional Automaton Zillion Infinity Neural Generative Exterminate Reverter.
** And in chapter 6:
-->'''Sayaka:''' Aphrodite A, immediate activation! number 1. Number 2. Number 3. Check! All green! Retention bolt, begin release!
* WithGreatPowerComesGreatInsanity: Oh dear god... hehe, [[IncrediblyLamePun god...]]
* XMeetsY: ''Anime/MazingerZ'' meets ''Anime/NeonGenesisEvangelion''.
** Actually you can tell the first arc is ''original'' ''Anime/MazingerZ'' ''manga'' meets ''EndOfEvangelion''. TheHero's girlfriend is brutally murdered? Check. TheHero crosses the DespairEventHorizon when he sees her impaled corpse? Check. He activates an HumongousMecha / EldritchAbomination with a penchant for going berserker and biting its enemies, and he accidentally uses it to trigger TheEndOfTheWorldAsWeKnowIt? Check. HumongousMecha ends up floating in space? Check. Pale-haired, non-human girl with powers beyond the human comprehension, who harbours strong feelings towards TheHero, and was designed by one of his relatives, gives him the chance to revert it? Check.
** Given that we are blending a UnbuiltTrope (the original manga was pretty dark) with a {{Deconstruction}} it is no wonder that that arc was a MindScrew.
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->''This is the memory of meeting Sayaka again after ten years... Remembering... Throbbing in my heart until then... Pounding... I thought at the time... People don't think with their head, they think with their heart... Everything wasn't inside of this meeting... But. That... Disappearing... everything... everything... Disappear... ing... What is it in there? My body? Then the me that's seeing... is who? [[spoiler:Mazinger]]... My rage. Sorrow. Pain. Every emotion, being swallowed by Z into one... No, becoming ZERO. Disappearing. Completely vanishing...''