[[WMG: Hiro's actual sin lies inside the TimeSkip.]]
What we saw in the first chapter wasn't the ''worst'' of it; in the two years since that event, Hiro did something far worse -- something like crossing the MoralEventHorizon, perhaps. Something that would make our DesignatedHero much less sympathetic if we knew the truth. The TimeSkip, therefore, is meant to hide this information until TheReveal in order to make it seem like less of an AssPull.
** Like maybe he killed Hikari.
** [[spoiler: Jossed on the idea that Hiro killed Hikari, as she is among the other group of sinners doing their own judging.]]
** [[spoiler: Confirmed on the fact that he did things. He spent the two years extensively researching and stalking the jury and judge of the trial of Atsuya's death, crafting the plan of the ''Judge'' game since he's one of the masterminds behind it.]]

[[WMG: This is a sequel to Doubt and Hiro is the "Wolf" for this game.]]
Not only does he get a rabbit mask, but in the cover page a person with a rabbit mask is next to him, wearing the same shirt the Wolves wore in Manga/{{Doubt}}.
* [[spoiler: Confirmed. Hiro is one of the masterminds of the entire game.]]

[[WMG: The fat guy with glasses will play a key part later on.]]
Why would a random character be introduced just to die on the exact same page? Why has no one come for the body? It seems to me that a fake-out is in order...Especially since in the mangaka's previous work [[spoiler:a character we thought was dead in one of the first chapters turned out to be [[FakingTheDead faking it]] and was the Mastermind behind the whole ordeal.]]
** [[spoiler:Of course, a good writer wouldn't use the same trick twice.]]
*** [[spoiler:Jossed, though it was likely an intentional RedHerring.]]

[[WMG: The guy with the lion's mask is [[Manga/{{Doubt}} Yuu]] all grown up.]]
* Jossed.

[[WMG: The "Wolf" is the pig-masked guy.]]
In the splash-page/page image, he's facing ''away'' from everyone else and is the one who is in the most shadows. And considering how the [[Manga/{{Doubt}} previous work]] had a clue on ''its'' splash page...
** Of course, Hiro is also facing away from us.
** That's actually the bear guy and he [[spoiler:[[KilledOffForReal was the first to go.]]]]

[[WMG: Kazu is the traitor.]]
* Something about him is just kind of fishy to me.
** [[spoiler:Confirmed. Though it's not because he wants to. The mastermind behind the judging [[IHaveYourWife has his mother]].]]

[[WMG: [[spoiler: Hiro being the culprit]] was a lategame writing decision.]]
* There is a number of pieces of information that suggest to me that [[spoiler: Hiro being one of the culprits alongside Hikari]] was something Tonogai only decided on close to the series ending. To wit:
** 1. [[spoiler: Hiro acts absolutely nothing like a culprit. He thinks about wanting to escape, purposes plans to make everyone live, reacts in horror to peoples deaths (even people he killed) and is at one point shown having a traumatic dream as if he thinks his life is in danger. None of this behaviour makes sense his he's the one killing.]]
** 2. We are shown all the events in between [[spoiler: Nobuyuki's last appearance and his dead body being found]] and there wouldn't be a point in between where [[spoiler: Hiro killed him.]]
** 3. There is very little {{Foreshadowing}} towards [[spoiler: Hiro being the culprit.]] Indeed, the only noticeable event could easily be interpreted as being something else entirely. In fact, at the end, [[spoiler: Rina notes that she suspected Hiro because he didn't seem to react to Asami attempting to seduce him, when he ''is'' shown reacting,]] almost as if the story attempted to insert a clue into a scene where it didn't originally exist.
** 4. There is a strong SevenDeadlySins motif to the early parts of the story that is virtually non-exsistent by the end and is almost completely irrelevant, which would suggest the story went through significant rewriting as it was running.
** 5. Most glaringly, [[spoiler: at the start of the series, Hiro wakes up in his room, handcuffed, reacts with shock when he sees the rabbit head in the mirror and says he was knocked out on the way back from school. If Hiro is the culprit, why is he handcuffed, why is he surprised at the rabbit head and why is referencing something that '''never actually happened!?''']]
* So yeah. In conclusion, my thoughts is that Tonogai originally planned for the culprit to be [[spoiler: Hikari]] but changed it so that [[spoiler: Hiro was the culprit as well]] because he either he felt it was [[CaptainObviousReveal too obvious]] (since [[spoiler: Hikari would be the only person who would know Hiro committed [[GreenEyedMonster Envy]]), that it was too similar to TheReveal in ''Manga/{{Doubt}}'' with the protagonist’s LoveInterest [[LoveInterestTraitor being the culprit]]]] or a combination of the two. Needless to say, it would explain the plot holes the story suffers from.
* I already mentioned on the theory below, but I think that before [[spoiler: Hikari would have drugged Hiro to make Hiro forget his participating ]] but it was later changed as [[spoiler: he was acting ]] probably so it wasn't as chiche or similar as other things like for example [[spoiler: his own manga Doubt ]] but maybe it would have been better or actually more original because it was planned [[spoiler: and either way she killed him in the end and that made it similar to Doubt in a way]].

[[WMG: [[spoiler:Hiro pulled a MemoryGambit.]]]]
He acts like he doesn’t know anything, and his thoughts are written as if he doesn’t know anything, because for most of the story he really ''doesn’t'' know anything. [[spoiler:Hikari]] likely removed his memories, then returned them at some point near the end, either to make him harder to detect or just to torment him before [[spoiler:killing him]].
* My theory is that something similar was the first plan of the story, well not exactly. I think that in the first draft just like in the final story [[spoiler: Hikari and Hiro planned revenge on everyone, but in this version she manipulated Hiro even more so she also drugged him so he lost memory of what he did]]. That's why on the first chapters [[spoiler: Hiro ]] would seem scared of being abducted [[spoiler: even in personal thoughts when he would have been faking. ]]

[[WMG: [[Manga/{{Doubt}} The Wolf]] [[HijackedByGanon is the true mastermind.]]]]
[[spoiler:Rei Hazama]] decided to make another game, and this time recruited [[spoiler:Hikari and later Hiro]] to help. [[spoiler:Hazama]] felt sympathy for their plight and decided to share the “gift” of revenge. Given how [[spoiler:Hazama disguised herself as Mitsuki’s dad]], it’s likely they did the same here by [[spoiler:disguising herself as Atsuya and gaining Hikari’s trust]].

So, [[spoiler:Hazama]] ordered [[spoiler:Hikari]] to kidnap Hiro, then [[spoiler:explained the plan before putting him under her control]]. Hiro [[spoiler:[[MemoryGambit lost all memories of being a Judge]] and acted perfectly normal]]. Then [[spoiler:Rei called Hiro at some point (or contacted him some other way) and hypnotized him into regaining his memories]], allowing him to [[spoiler:carry out his end of the plan]]. Finally, either [[spoiler:Rei-as-Atsuya]] orders [[spoiler:Hikari to kill Hiro]] and then possibly [[spoiler:kills Hikari herself]] to cover their tracks, or [[spoiler:Hikari acted on her own initiative when killing Hiro]]. Alternatively, [[spoiler:Hikari ''is'' Rei under a new identity she created to coninve the world she was dead after faking it, though this is less likely]].

[[spoiler:Either way, [[spoiler:Rei has [[InvincibleVillain once again killed many people and gotten away with it all]], this time by [[TheScapegoat blaming it on one of the judges from the incident]]]].

[[WMG: The Wolf is also behind the Secret game.]]

[[spoiler:Rei hypnotized one of the nurses to steal the sleeping pills, then fed it to the bus driver, so she could pose as Mitomo’s sister and trick him into setting up the game. Why? By this point, it’s ForTheEvulz, or revenge against the world as she calls it.]]

[[WMG: [[Manga/{{Doubt}} The Wolf]], The Judge and Mitomo are [[VisualNovel/ZeroEscape Zeroes.]]]]
How could they not be, given the similarities?

[[WMG: [[Manga/{{Doubt}} Rei Hazama]] is [[VisualNovel/ZeroEscape Akane Kurashiki.]]]]
'''Warning! Spoilers for Doubt and Zero Escape follow!'''

[[spoiler:Or rather, Rei is the original Akane. In this prime timeline, Akane’s quest for vengeance began when her rabbits were killed in middle school. Ever since then, she set out to learn hypnosis, or “mind-hacking” as Delta called it, to get revenge. At some point, she changed her name (likely to hide her crime), dyed her hair, and became a famous hypnotist. Her father was never accused of being the Heart Ripper Mira. Instead, they died when people began questioning Rei’s abilities, and she lost her fame. Her parents killed themselves, so as vengeance she created the Rabbit Doubt game- and the first Zero, The Wolf. She created the Judge and Secret games later using the method seen above.]]

[[spoiler:At some point, she gained a [[AGodAmI god complex]] and began believing her mass murder was divine retribution. So she hacked into the world’s nuclear reserves and triggered a nuclear war- and became the Religious Fanatic. After destroying the world, she traveled around looking for any remnants of humanity. She found a bomb shelter, and inside was Sigma and Diana. They were about to send their children through the transporter, but she discreetly hopped in with Delta. Her original self stayed back and killed everyone in the shelter. Now transported to another time, she took Delta in as a mother of sorts.]]

[[spoiler:She told Delta of the religious fanatic, leaving herself out of it, to convince him to create [[ReligionOfEvil Free The Soul]], with her as its god. Together they recruited Lord Gordain and convinced him to create his game, and eventually convinced Ace/Gentaro to create the first Nonary Game. Rei’s reason for doing all this was to learn about the morphogenetic field and gain control of it.]]

[[spoiler:But in doing so, she screwed over her self from this timeline. Akane Kurashiki was a test subject. [[NeverMyFault She grew angry, believing that Free The Soul betrayed her]]. So she connected Akane to Junpei of the future, and plotted Ace’s downfall, secretly influencing Akane (possibly via mind-hacking) to create the second Nonary game. Then she convinced Delta to create Radical-6, and unleashed it upon the world. She had her other self create the AB game as well, and went for Dio next. Finally, she plotted to put down Delta himself. ]]

[[spoiler:[[TheBadGuyWins And in the end, her plan went off without a hitch.]] As of ZTD’s ending, she is attempting to nuke humanity (possibly using Gordain as a mind-hacked proxy), with the intention of creating a never-ending literal CycleOfRevenge across timelines, so that the world itself may suffer her wrath over and over and over again. [[DisproportionateRetribution And all for the sake of a few murdered rabbits]]. Only time will tell if the three teams are able to stop her and her mad ambitions.]]