Beware the unmarked spoilers!!
Zerodimension Neptunia Z: Twilight of the Desperate CPUThree years have passed since the permanent connection between Hyperdimension and Ultradimension was established. With the era of peace continuing throughout the Gamindustri, Neptune and Nepgear continue their lives until Histoire warns them about "CPU Shift Period", the moment where the public will attempt to discredit and oust their CPUs in favor of newcomers. However, before Neptune and Nepgear prepare the countermeasures, they stumble across an old console which transports them to another alternate dimension: Zerodimension. Unlike any other dimension, this new dimension is a ruined wasteland inhabited by monsters only.
During the exploration, the two finally meet a survivor and the newcomer of this installment, Uzume Tennouboshi. Neptune and Nepgear learn that they are unable to use their HDD due to the absence of Shares. The same problem happens to Uzume too. In order to activate their HDD powers, the trio decide to explore the land to find Share Crystals, which they use to empower themselves enough to reclaim the land from the invading monsters.
Neptune and Nepgear learn from Umio, Uzumes fish sidekick, that Uzume, unlike any CPU, has a unique power that may trigger when the party needs or wants according to situation and condition. Much like Neptune in the first game and its AU remake, she is an amnesiac who remembers nothing of her own people or the disaster which destroyed her world, but believes it to be the work of a group of giants known as Dark CPU.
In the following day, the Hyperdimension Planeptune CPUs and Uzume decide to explore the Zerodimension further in order to find a bunch of Share Crystals. However, their exploration doesn't go smoothly, as the trio manages to locate the Share Crystals, they are greeted by none other than Neptune and Nepgears old friend, Arfoire. Afroire then summons the Dark Purple to attack the trio. However, during the dire situation, the trio senses the Share Energy flowing through their bodies. Without wasting any time, Neptune and Nepgear transform to their goddess form, Purple Heart and Purple Sister respectively. Glancing at their HDD form and the word Planeptune, Uzume suddenly remembers something. But like Neptune and Nepgear, she proceeds to transform to her HDD form, Orange Heart, and the battle against Dark Purple ensues. However, the CPUs manage to defeat Dark Purple, thus forcing Arfoire to retreat.
Nepgear starts to repair the transportation device to send her and Neptune back to Hyperdimension. However, Arfoire lays siege to the facility. Nepgear manages to send her sister back to Hyperdimension, but she remains behind to defend Uzume from Arfoires attack, though the two are forced to abandon the facility and retreat. Back in the Hyperdimension, Neptune finds Histoire in an unconscious state due to her being an artificial life-form who overloaded as a result of her linking the two dimensions to bring Neptune home. With the help of the other CPUs, Neptune sets out to First-Gen CPUs Sanctuary, in order to find an ancient artefact belonging to the original CPU of Planeptune called Sanshiros Soulful Patch, so she can reboot Histoire. Neptune manages to acquire the artifact and proceeds to restore Histoire, hoping she can bring her sister home.
Meanwhile, in the Zerodimension, Nepgear and Uzume travel to the latters safe house, but are intercepted by Arfoire. Luckily, with the help of older Neptune, they manage to defeat and capture her. After arriving at the safehouse, the older Neptune reveals that she is a dimension traveler who comes from a Planeptune under the rule of Plutia/Iris Heart, the previous protagonist and playable character from Victory/Re;Birth3. She came to the Zerodimension with the power of Croire (the former Oracle of Tari and instigator, also from Victory/Re;Birth3) after capturing her with her Nep Note, though Croire escaped.
Arfoire manages to escape after tricking the party and finds Croire. After receiving the remainder of Taris CPU power from Croire, Arfoire frees Dark Purple from the Sharing Fields pocket dimension and fuses with it. However, the trio manages to recaptures Croire. Despite the fusion between Arfoire and Dark Purple with Taris CPU power, the party are able to re-confine the fused giant by boosting Uzume's powers with Planeptune's shares, creating a cross-dimensional portal in the process. The Hyperdimension Neptune joins the fray and successfully destroys the giant, although the portal becomes unstable. Neptune and Nepgear bid a farewell to their new friend Uzume. Uzume and Umio plan to rebuild the Zerodimension, though the older Neptunes fate is left unknown.
Hyperdimension Neptunia G: The Golden Leaders, Reconstructors of GamindustriSeveral days later, after Neptune and Nepgear return to their home dimension, the CPUs hold an urgent meeting to discuss the CPU Shift Period, which is now in full effect. A number of hoaxes pollute the media and internet in regards of CPUs, resulting in a significant decrease in their Shares. In order to regain public faith, the CPUs decide to work together to unite the Gamindustri people by holding weekly festival. The festival proves to be successful as the Shares increased significantly until the final day when the CPUs hold a friendly rivalry tournament, which they call G1 Grand Prix. Before the tournament begins, they are suddenly interrupted by a mysterious group called Gold Third which challenges and swiftly defeats the CPUs. Everything goes chaotic, with the CPUs being humiliated with their defeat. In the midst of chaos, the older Neptune suddenly appears and seems to stop a mysterious girl who wants to mess up the whole Gamindustri. The mysterious girl, however, ignores the older Neptunes plea and proceeds to restructure the whole Gamindustri.
Elsewhere, the mysterious girl asks Affimojas what he desires with this newly restructured Gamindustri. Affimojas answers that he wants wealth. Despite that, he doesnt have any desire to wage a conflict with armed weapons. Instead, he relies on information as his own weapon, and thats the reason why his organization exists. The mysterious girl seems impressed with his boasts, but she demands his promise to give the console to her. Affimojas responds that he will keep his promise, as well as confirming that his loyal subordinate, Steamax, is on the move. The mysterious girl provides Affimojas by lending her friends. However, she warns him to not make her wait any longer.
The CPUs finally awake, only to find that their own people have forgotten them and each of the four members of Gold Third now rules one of the four nations. The CPUs decided to return to their respective Basilicoms, followed by the Candidates to investigate each nations situation, all while finding out who is responsible for this mess. Despite their attempt to keep in contact, the networks prove unstable. In addition, planes are completely grounded and boats cant leave port, leaving each nation isolated. Worse, vicious new monsters also appear, along with four mysterious golden towers.
Neptune's StoryNeptune reunites with her old friend IF and follows her on an investigation in Sakura Tree Row. During the investigation, IF treats her like a stranger, as she calls her a little kid, thanks to the mysterious girls memory alteration. However, IF suddenly remembers Neptune after the latter rescues her from Arfoire, who is revealed to have survived and escaped from the Zerodimension. The two managed to defeat Arfoire, but Arfoire is rescued by Steamax. Neptune and IF returns to Planeptunes Basilicom as the aforementioned nations citizens regain their memories, one of them being Compa. The three head to the Basilicom where Histoire welcomes them and reveals that B-Sha, the current ruler of Planeptune, is even lazier than Neptune. Not only that, she is also afraid with monsters.
At the park, Neptune and B-Sha have a pep talk. During the talk, is revealed that B-Sha never had any intention of taking over Neptunes role. She also reveals that she scared with monsters because she almost attacked by a monster during her childhood. In order to control her fears, she looked up some heroes who bravely fight monsters and evil-doers. To further her goals, she decides to join Gold Third, but even so, she thinks its impossible, as her nightmares become worse. She might be okay when dealing the smaller ones, but when dealing the bigger ones, she become useless. Neptune cheers her, saying even she is incapable of fighting every monsters, at least she always saves children from bad guys. Neptune also suggests she and B-Sha work together, with B-Sha providing the security and Neptune providing the extermination. B-Sha agrees and decides to call her Nep-Nep from here on out.
Neptune, IF and Compa later capture Warechu, now become a resident crook of Planeptune. IF forces Warechu to spill his guts about the AffimaX syndicate. In order to please Compa, Warechu reveals the names of AffimaX members, including himself, Arfoire, Steamax and their leader, Affimojas. Meanwhile, Steamax infiltrates the Basilicom, frees Warechu and steals the console. The party manages to chase and defeat Steamax, but are forced to join forces with him to stop a brainwashed Warechu and B-Sha, who are attacking Planeptune, though Steamax escaped with the console.
Noire's StoryNoire returns to Lastation with her sister Uni, only to find out she is now a fugitive pursued by her own national police. Noire is forced to leave her sister behind and run from her pursuers until she is exhausted and collapses. Luckily, Noire is rescued and nursed by K-Sha. The two become friends and K-Sha reveals that Lastations Gold Third leader resigned and a corrupt private military company called The Order is now in charge in the nations Basilicom.
Noire secretly aids Lastation by defeating some monsters which are attacking civilians. However, upon her return to the city, she is forced to reveal herself in front of Lastation soldiers when K-Sha is about to be interrogated about her whereabouts. Noire surrenders to save K-Sha, though Uni soon arrives and rescues her sister from jail. Noire and Uni later proceed to their countrys Basilicom.
Noire and Uni arrive at Lastations Basilicom. While they're looking for some clues, they are greeted by a female member of The Order who claims to work as a Lastations Basilicom staff member. Noire tells her that the Basilicom belongs to her, but the female Order member replies that she remembers Noire and Uni as the rulers of Lastation, and she tells the former that her role as the CPU is in the past. Noire demands that she stop the invasion, but the female Order member seems seems to not care if citizens are hurt or killed because of the Orders actions, as long as they get whatever they want, with the hijacked Basilicom. The female member later calls guards to capture Noire and Uni, then rubs in the fact that Noire and Uni cannot hurt those who should be protect. They dont have any choice but to stand back and retreat.
After retreating from Lastations Basilicom, Noire and Uni devise a plan to prevent the Order mercenaries from invading other nations by defeating the new monsters, so they cant use the monsters as weapons. Noire also adds that the security will become tighter after the incident, thus a direct confrontation has become nearly impossible. Uni thinks that this is kinda trivial, but its worth it to try. Before Noire and Uni start their mission, the former is greeted by K-Sha. Noire introduces her sister to K-Sha, though Uni is confused at first. Noire and Uni later depart to start their mission, along with K-Sha, who is now a scout for them.
Assuming his disguise as "Jiro", Steamax meets Uni for the first time in a book store and starts having an interest to her. Later, Uni and Noire are greeted by K-Sha, informing them there are new monsters inside the subway systems. Before Noire and Uni go to the subway, K-Sha wants to join once again, but Noire doesn't allow her to join for the sake of her safety. K-Sha understands and acknowledges her warning.
Thanks to Noire and Unis effort, many people start to put their trust in them. K-Sha greets them, and the trio take a rest at the hotel.
At night, K-Sha dreams that Noire and Uni once again go together to complete some quests. She remembers the time when she became Noire and Unis observer. Later, the mysterious girl appears in her dream and feels pity for her situation. The mysterious girl then tells K-Sha that she is jealous towards Uni because she is Noires younger sister. She also suggests that K-Sha kill Uni and make Noire her one and only friend.
In the next day, Noire is asked by a Lastation civilian to collect a special ore for his work. Meanwhile, Uni wonders why K-Sha dislikes her, despite never doing anything bad to her. Suddenly, she is shocked by Noires sudden appearance. Unknown to her, this "Noire" is actually the mysterious girl in disguise, as she pretends to be out of character in order to incite more jealousy on K-Sha's part. After the real Noire collects enough ore for the citizen, she returns to the hotel with Uni, whom the latter confused with her sudden behavior change. K-Sha becomes more jealous, while the mysterious girl wonders what she will do next and seems more than happy when she manages to completely instigate more jealousy in K-Sha.
The following day Uni is called by K-Sha, seemingly to discuss something. Suddenly, K-Sha brandishes her gun and tries to kill Uni. Hearing the ruckus in Unis room, Noire appears and asks K-Sha abut her personality change. K-Sha later challenges Uni to a one-on-one deathmatch at Lastations Golden Summit tower, with Noire as the prize. Arriving at the top of Lastations Golden Summit tower, K-Sha appears in front of Noire and Uni and reveals that she is Lastations Gold Third member. Noire suggests that K-Sha solve the problem peacefully, but its too late. K-Sha is now become similar to a battle hardened (if also bloodthirsty) soldier. Noire has no choice but fight K-Sha, taking Unis place and winning. After the battle, Noire gives K-Sha a pep talk about friendship. Realizing that shes not alone, K-Sha apologizes and the two agree to be friends once again.
The mysterious girl seems disappointed with her plan being thwarted. In this scene, we also learn that the female member of the Order is also working in cahoots with the mysterious girl, as she wants to destroy the golden tower once K-Sha is no longer useful. The mysterious girl asks the female member how she will realize the plan, but the female member responds that she and her fellow Order members have already prepared something for when this kind of situation comes.
Back at the hotel, K-Sha retells her experiences as a member of The Order to Noire and Uni. She has been trained to be an expert soldier by the Order, to the point that her personality drastically changes when she holds a gun. At first, she never held any doubts and just followed orders. But when she saw normal girls doing normal activities, she desired to be normal. At some point, she obtained the golden power and became the Lastations representative of Gold Third, and tested its powers to fight the CPUs during the final day of the festival. She and the rest of Gold Third ended up winning and as a result the world suddenly become a mess ever since. She also reveals that she doesnt have any capabilities to rule a nation, fears to lose her normal life, and thus she left any national affairs to the Lastations Basilicom. But suddenly, the remains of the Order found her and tasked her to perform the political assassination of Noire. However, when saw Noires face, she couldnt kill her. Finally, she expects the Orders movement to nullify her golden power. Understanding the situation, the trio proceed to the Golden Summit, with K-Sha waiting at the bottom of the tower.
Arriving at the top of Lastations Golden Summit for the second time, Noire and Uni greet the female Order member, this time with her shiny Anti-CPU Weapon. Noire and Uni, as Black Heart and Black Sister respectively, manage to destroy the weapon. However, they are unaware that the weapon also contains some sort of poisonous gas. When the female member gloats over her victory, shes tranquilized by K-Sha and the latter proceed to cure Uni by creating a vaccine from her own blood. But suddenly, she turns hostile again after being manipulated by the mysterious girl once again. Noire and Uni are forced to fight her once again and manage to snap her out of a funk. Realizing the Gold Crystal is driving her insane, K-Sha destroys the crystal herself and the three agree to be friends again, this time for real.
Blanc's StoryAfter arriving at Lowee, Blanc is greeted by a Lowees Guild Woman. Like the rest of the CPUs, she doesnt remember her role as Lowees CPU, as if saying her role is a relic in the past. However, Blanc learns from her that Rom and Ram await her at Lowees capital city. Using a shortcut, Blanc proceeds to the capital, but shes intercepted by a bunch of strange monsters, which she's never seen before. After defeating the monsters, Blanc decides to investigate its whereabouts, in case she found another one. However, one of the monsters attacks Blanc and renders her unconscious. Luckily, a young woman saves her in the nick of time, before herself being killed by the monster.
At the hotel, Blanc is awakened, and the woman who rescued her introduces herself as C-Sha. C-Sha asks if Blanc is not from Lowee, but the latter replies that she is indeed born and raised in Lowee. However, Blanc is unfamiliar with the new License system and asks about it. C-Sha explains the License system is a system where all Lowee residents are meticulously managed. All that matters is the profession they have. Even their job is decided at birth. The only saving grace is people can choose their side job. With this system, Lowee become an authoritarian society, resembles the nation in the old days. Hearing this, Blanc is unamused and states her own nation used to be a safe and fairy tale-like land. Blanc decides to wait until tomorrow to search for Rom and Ram.
In the following day, Blanc registers herself as a member of Lowees Guild. Meanwhile, C-Sha is approached by a Lowees official named Azna=Leb. C-Sha is tasked by Azna=Leb to assassinate Blanc, whom Azna=Leb claims is the source of delusionary monsters, but C-Sha refuses. Back at the Guild, Blanc is accepted as a Hunter and her search for Rom and Ram begins.
Arriving at the Player 2 Park, Blanc and C-Sha start their search for the twins. However, they are greeted by a monster, seemingly possessed by some sort of red fog. After Blanc defeats the monster, C-Sha explains that the possessed monsters are in delusionary state, much like what happened in Planeptune. Blanc decides to return to the city, in order to gather more information about her sisters. Elsewhere, Rom and Ram are also searching for their sister. It is also revealed that the twins also became Hunters. While the twins are searching, they are greeted by another delusional monster. They try to attack the monster with their magic, but their magic doesnt work. The twins have no choice but retreat.
A few days later, Blanc continues her daily life as a Hunter. She gains more popularity with the Lowee citizens and her fellow Hunters because of her helpful nature. But Blanc claims that while she is helping those who need her help, she is not trying to become famous or anything. Back at the hotel, Blanc and C-Sha cannot find any clue about the twins whereabouts. Later, both Blanc and C-Sha chasing each other after the latter secretly peeking her during night time. However, they were suddenly attacked by monsters, which Blanc fends off. Later, when Blanc wants to continue the bickering, C-Sha once again runs away. Somewhere at the Lowee's capital, C-Sha is greeted by Azna=Leb asking her if she had assassinated Blanc yet. Azna=Leb also warns C-Sha that the same excuse will not work a second time, so she better get to it.
Several minutes later, C-Sha informs Blanc that she has another clue to Rom and Rams whereabouts. After learning some information from Financier, Blancs trustworthy maid, Blanc and C-Sha head to the Hex Grasslands. At the Hex Grasslands, Rom and Ram are cornered by a delusional monster, but thankfully Blanc manages to save them. After rescuing Rom and Ram, they come back to the hotel to have a rest.
The following day, Blanc meets C-Sha, whom plays along with Rom and Ram. While discussing their personal matters, Financier suddenly calls Blanc, informing her that theres a person who wants to talk to her personally. And that person is none other than Azna=Leb. Like the female Order member, he also remembers Blancs role as the CPU of Lowee. Claiming the nation itself became a dystopia due to the License system, he demands that Blanc work with him. Blanc agrees, but at the same time she learns that C-Sha is currently a ruler for Lowee. According to the information that Azna=Leb provides, C-Sha is the one who is responsible for the creation of the delusionary monsters appearing in Lowee. Blanc is also surprised that she is tasked by Azna=Leb to assassinate C-Sha, however Azna=Leb decides to let Blanc make the decision herself, since the revolution will begin sooner or later, regardless.
Blanc asks C-Sha about her origins, and the latter confirms that she is the Lowee representation of Gold Third, and like K-Sha, she has no intention of being a leader. C-Sha wants to clean up the mess she made after the incident, but unfortunately its a really big mess. C-Sha also reveals that shes the one who's responsible for the creation of delusionary monster. She tells Blanc that at some point she had a series of nightmares. Ever since she started seeing her dream, a strange red fog suddenly leaked from her body. More monsters became out of control because of the fogs influence, and thus became delusionary monster. She decided to be a Hunter, so she could reduce the numbers of monsters, all while atoning for her mistakes. Blanc also asks C-Sha about the License system, and C-Sha replies that the aforementioned system was already present in Lowee since the G-1 Grand Prix incident. C-Sha tries to find out who is responsible for the problem within Lowee. Suddenly, Azna=Leb appears and orders his Revolutionary Army to arrest C-Sha. Blanc becomes pissed off and demands that the Revolutionary Army release C-Sha, but they ignore her. Azna=Leb, like the female Order member, also rubs in the fact that Blanc cannot hurt those who should be protected, and then he leaves her.
A few days later, Blanc is still thinking of how to save C-Sha and the twins badly want to rescue her. However, the three are secretly listening to a conversation between two Lowee citizens about C-Shas execution. Meanwhile, in the Lowee prison, C-Sha feels bitter about being betrayed by her best friend. She also has a nightmare where Blanc is the one who executes her. While C-Sha listens to a conversation between two members of Revolutionary Army, she asks one of them why Azna=Leb requested her to assassinate Blanc, all while also creating the so-called Revolutionary Army. One of them replies to her that Azna=Leb apparently had his eye on Blanc because of her closeness to C-Sha. He was also the one who gave out information on her. In other words: Blanc was used by Azna=Leb. Later, Financier appears and informs C-Sha that she is no longer a follower of Azna=Leb and has decided to side with Blanc. Financier also tells C-Sha that its her fault in the first place that Azna=Leb and Blanc were brought together.
After refreshing themselves at the hotel, the three begin their rescue mission of C-Sha. Before they leave, Financier informs Blanc that Azna=Leb put her name on the Revolutionaries wanted list. Blanc becomes furious after learning this, but Financier warns her that theres a possibility she will be captured if Blanc recklessly faces the Revolutionary Army without any preparations whatsoever. Blanc understands, but suddenly the Guild Woman arrives and also informs her of this by giving her a wanted poster, and tells her that the truth is she is not a terrible person, with which Rom and Ram agree. Blanc and the twins decide to leave the hotel, and tell Financier and the Guild Woman to do their best to not get themselves involved anymore.
C-Sha has another nightmare about being executed. Meanwhile, Blanc and the twins devise a plan to rescue C-Sha during the execution. Suddenly, they hear a noise from a Lowee citizen. Through Financier, the three learn that all residents are escaping from a horde of delusionary monsters. Blanc decides to fend off the monsters, while Rom and Ram provide protection for the Lowee residents. Back at the prison, C-Sha is greeted by Azna=Leb, who tells her that her execution day has come. However, he is informed by a Revolutionary member about a horde of delusionary monsters arriving at the prison. Azna=Leb later orders his Revolutionary Army to escape rather than head-on, and haphazardly tells his subordinates they can simply rebuild the city if its destroyed, as well prioritizing his life over those of the Lowee citizens.
Blanc starts her attempt to fend off the monsters alone, but shes outnumbered. When all hope seems lost, Financier arrives with reinforcements; consisting of Rom, Ram, the Hunters and C-Sha, whom the latter freed by Financier. Thanks to their efforts, Lowee is saved in the nick of time.
Upon their return to the Lowees capital, Blanc and C-Sha feel grateful the city wasn't destroyed. Azna=Leb appears and orders the Hunters and his subordinates to capture the Golden Pair, but the former refuse. Breaking the silence, one of the Revolutionary members and Financier give their testimony about his callousness. Sickened with his callous ramblings, Blanc then punches Azna=Leb and chews him out by telling him the Lowee citizens arent as weak as he thinks. Not wanting to miss the spotlight, C-Sha loudly proclaims herself as a Lowees representation of Gold Third and apologizes if she failed to carry out her duties. The Lowee residents accept her apology. Everything seems to end happily ever after until the mysterious girl once again starts messing around by hijacking C-Shas body, forcing her to run away from Blanc, Rom and Ram.
At the Guild, Blanc learns from the Guild Woman that C-Sha has gone into the Golden Summit tower. Financier adds that the tower supposedly cannot be opened. Blanc replies to Financier that C-Sha is part of Gold Third. Blanc and the twins then proceed to the Lowees Golden Summit tower. After Blanc, Rom and Ram arrive at the top of Lowees Golden Summit, it is revealed that C-Sha already destroyed the Gold Crystal, her power source. Despite that, she's still in a uncontrollable state. When C-Sha tries to suppress her power, the mysterious girl proceeds to use her body as her own vessel. Blanc, Rom and Ram have no choice but fight C-Sha. Despite their combined efforts, the Lowee CPUs still cannot snap C-Sha out of her funk. Rom and Ram try to persuade C-Sha by telling her they should doodle Blanc's literature together. Blanc becomes furious and proceeds to chase the twins, but unknown to her, their antics unintentionally help them save C-Sha from the mysterious girls influence. After being rescued, C-Sha gives her thanks to the three, and also apologizes for making them all worried. The four then proceed to return to the city.
The mysterious girl seems disappointed that her plan is foiled, but at least shes impressed when that Affimojas and Steamax managed to obtain the third item in Azna=Lebs mansion basement. Back at the city, Blanc and C-Sha are bickering with each other, to the extent that they once again are playing cat-and-mouse, although this time with Rom and Ram. But C-Sha, once again thanks Blanc for helping her. Blanc responds to her with a welcoming smile.