This is a blog regarding and explaining the cosmology of the Hyperdimension Neptunia series.

Dimensions[]

Hyperdimension Neptunia's universes are classified as "Dimensions", of which there are multiple, separate dimensions that are found within the canon, as well as an implied dimension.

Hyper Dimension[]

The Hyper Dimension (超次元, Chō Jigen) is the main dimension of the series, and is the primary location for a large portion of the canon games. It is where Guardian Goddesses Neptune, Noire, Blanc, Vert, and former Guardian Goddess Uzume Tennouboshi originate, as well as Goddess Candidates Nepgear, Uni, Rom and Ram, and Maho. It is home to the continents of Gamindustri and the PC Continent.

Gamindustri is referred to as both "a world which exists outside of (our) reality"^[1] and "a world in a faraway dimension"^[2], and its location is described as "away from the realm of humans"^[3]. Its current dimensional coordinates stand at "306 : 130 : 873 : 046 : 305 : 830 : 52 : 30 : 93"^[4].

Neptunia games Hyperdimension Neptunia mk2, Megadimension Neptunia VII, and Neptunia: Sisters VS Sisters use the Hyper Dimension as a main setting either most of, or all of the time.

Ultra Dimension[]

The Ultra Dimension, or God Dimension (神次元, Kami Jigen) in the Japanese version, is a dimension that first makes its canonical debut in Hyperdimension Neptunia Victory. Much like Hyper Dimension, it also is home to a Gamindustri and PC Continent. However, the Ultra Dimension's Gamindustri seems to be earlier in its lifespan, as the nations of Lastation, Leanbox, and Eden are constructed within the game's story instead of being nations that exist already^[5].

In the past, the Ultra Dimension experienced an event known as "The Great Crash", which involved the collapse of the nation Tari, ruled by Goddess Rei Kiseijou, plunging Gamindustri into a state of confusion and poverty. However, thanks to the rise of the nation Lowee, ruled by Goddess Blanc, Gamindustri saw an era of uprise and gaming consoles were eventually making the world-go-round again.

Ultra Dimension and Hyper Dimension are noted to be different dimensions (multiple^[6] times^[7]), and Hyper Dimension has been referred to as "the other side"^[8] by the Ultra Dimension's Histoire. Nepgear, whilst she was present in Ultra Dimension, was planning to develop a device that allows for cross-dimensional communication^[9]. Duplicate characters, like Histoire and Rei are often titled by "from Here" or "from There", creating a distinction between the same characters of the different dimensions.

On top of this, Ultra Dimension has been noted to have a different time-flow than Hyper Dimension; that is, for every one day that passes in Hyper Dimension, a year passes in Ultra Dimension. Within Victory, multiple intervals^[8] of years^[10] are stated or shown^[11] to pass^[12], whereas in Hyper Dimension, only intervals of days pass. This difference in time-flow was later stabilized in the True Ending of Victory so the two dimensions' timeflows can run the same^[13].

It is stated by Histoire that conventional rules do not apply across dimensions^[8], in reference not only to the different time-flows, but also the different ways that the dimensions seemingly work. This is shown primarily in the way that Goddesses are created and function between the two dimensions.

• In Hyper Dimension, a Goddess is created^[4] and born directly from Share Energy^[6], and are shown to be reliant on Share Energy, for without it, they will perish^[4].
• In Ultra Dimension, a Goddess is not created from Share Energy. Rather, an individual must go out and search for a CPU Memory to become a Goddess. There are (unknown) prerequisites to becoming a Goddess, however, and those unqualified will turn into a monster^[6]. Upon losing their Share Energy, the Goddess will retain the inability to age, but will be stripped of their power^[7].

The only known way to enter the Ultra Dimension is via cross-dimensional portals (seen^[14] several^[10] different times^[7]). It was later stated in Sisters VS Sisters that the path to Ultra Dimension was cut off^[15]; the official plot summary of Sisters VS Sisters that the use of the Magiphones severed the contact with the Ultra Dimension that was established by the gate in Victory, and the official Japanese Compile Heart website also states that the connection to the Ultra Dimension was cut off.

Heart Dimension[]

The Heart Dimension (心次元, Kokoro Jigen) is a dimension first appearing in Megadimension Neptunia VII. This dimension was created from the dreams of a sealed away and sleeping Uzume Tennouboshi, with the basis of said dream being the destruction of Gamindustri^[16].

Heart Dimension possesses the abnormal ability of turning any person's dreams into a reality. This ability is shown through the dreams of Neptune, Noire, Blanc, and Vert all becoming reality, and the main cast members being able to enter them as though they were truly real locations.

In the center of the Heart Dimension is the Share Crystal of the sealed Uzume. This Share Crystal is the crystallized remainder of the Shares Uzume had inside her when she was sealed away. Its shattered appearance is also not incidental, as the shards of this Share Crystal are scattered all throughout the world of Zero Dimension.

Much like Hyper Dimension, Heart Dimension possesses its own coordinates. However, due to Kurome constantly shifting Heart Dimension's position within the multidimensional space, it has no definite set of coordinates^[4]. The dimension itself can only be accessed through use of cross-dimensional portals, or tears in the fabric of space-time which connect the dimensions through gateways.

Zero Dimension[]

The Zero Dimension (零次元 / ゼロ次元, Zero Jigen) is a "dimension" located outside of the Heart Dimension, also created from the sealed Uzume's dreams, though it was originally a part of Heart Dimension^[16].

Zero Dimension is a destroyed, lifeless world where no humans reside after they were seemingly wiped out by entities known as the Dark Goddesses. The rips in the sky are cracks in space-time, and such destruction was caused by the Dark Goddesses themselves^[17]. This is later revealed to be because of Kurome's ambition to break the dimensional boundaries of Heart Dimension after being sealed away. There are also various Share Crystals scattered across the land of Zero Dimension, which Uzume uses to supply herself with Share Energy for fights. These Share Crystals are later revealed to be the shards of the large Share Crystal in the center of Heart Dimension^[4].

However, despite it being called a dimension, it is not actually a real dimension. It is described by Kurome as an entrance to Heart Dimension, rather than Zero Dimension being its own place. The dimensional coordinates that were first being measured in Zero Dimension are actually Heart Dimension's coordinates.

The way to access Zero Dimension appears to only be through the use of the Swirl Console, the same device that Uzume was sealed away in, and pressing a button on the console opens a portal that grants entry to Zero Dimension.

Super Dimension[]

The Super Dimension (超次元 Chō Jigen [not to be confused with the Hyper Dimension]) is a dimension that appears in the original Hyperdimension Neptunia^[18] and it's remake, Re;Birth 1^[19].

It was once the main (and only) dimension in the series, but due to the release of Hyperdimension Neptunia mk2, that was no longer the case. Despite this, as seen in Re;Birth 1, the Super Dimension can still be accessed by characters from Hyper Dimension due to the Makers of said dimension visiting, such as CyberConnect2^[20].

Whilst similar to Hyper Dimension, there are a few key differences in how the Super Dimension works, with Re;Birth 1 making even further changes that differentiates it from it's original counterpart.

• Unlike Hyper Dimension, the Goddesses aren't born from Share Energy, even though it does exist within the Super Dimension. Rather, they were created by the Original Goddess splitting her power into four equal parts. This "Original Goddess" is even said to be the mother of the four Goddesses.
• A realm unique to this dimension, Celestia, exists. Celestia is the world above the human world, and is where the Original Goddess, and by extension the four Goddesses, lived. This setting is where both the original game and Re;Birth 1 begin, as the Goddesses are engaged in the Console War.
  • In this realm, the Goddesses never get tired or hungry - allowing them to remain in Goddess Form indefinitely when residing there. This has allowed the Goddesses to fight for "thousands of generations"^[21] or "hundreds of years"^[22].

Original[]

In Hyperdimension Neptunia for the PlayStation 3, at the beginning, there was only one Goddess: Arfoire. After losing control of her powers, vowing to never misuse them again, and not wanting to rule the whole world by herself, she split her power over time to form five different beings. These beings became Histoire, Purple Heart (Neptune), Black Heart, White Heart, and Green Heart.

The Guilds across the Super Dimension, and it's members, were commonly labelled and referred to as a group of "Heretics", due to worshipping a different Goddess that is different from the ones on their native land. It's creation was due to the major purge on Heretics in Leanbox, whom fled to Lowee and established Guild City there.

Re;Birth 1[]

A lot of the features and overall world structure in Re;Birth 1 are, for the most part, similar to the original game. However, there are notable differences:

• The Guild functions the same as it would in Hyper Dimension, and serves under the Basilicom, unlike how the Guild functioned in the original game.
• The Original Goddess and Arfoire are two completely separate beings, whereas the original game made them the same entity.
• The True Ending shows the Goddess Candidates existing in this dimension^[23] - having been birthed from the Shares of all four landmasses individually being "inflated". This does not happen in the original game, as the True Ending of the original game sees the four Goddesses give up their powers to Histoire to create a new Goddess, with the four Goddesses becoming humans and eventually passing away from old age far into the future.

Game Maker Dimension[]

The World of Game Maker, which is simply an alternate Gamindustri, is a dimension explored by the Ultra Dimension Neptune in Neptunia: Game Maker R:Evolution. This dimension is where the Failure Goddesses - Pipi, Jarga, and Lideo - reside.

Long ago, there was a lone Goddess who had created a game, essentially inventing video games. Afterwards, there were many other Goddesses whom took interest in this video game, and decided to create their own games, leading to the "Era of Makers"^[24][25]. However, this era would eventually enter two separate dark ages due to a monstrous entity known as Zaikopath wreaking havoc across the world.

In the first dark age, the Goddess of F-Sha's unnamed homeland had created a cursed game with the purpose of forcefully enticing consumers to play and enjoy it. However, the resentment of the workers as well as the unsatisfactory thoughts towards the game from consumers caused an onrush of returns of the game. This result in a collage of negative emotions, giving birth to Zaikopath. Zaikopath rampaged through the country, destroying the entirety of F-Sha's homeland and leaving her as the only survivor. The Goddesses, unable to defeat Zaikopath, had no choice but to seal it away and hope it never returned^[26].

In the second dark age, the trio of Goddesses, whom would later become the Failure Goddesses, were the catalyst for Zaikopath's return. As they contiunued to create extremely poor quality games with no regards for the consumers whatsoever, this resulted in a massive unplayed and unwanted stock of games, resulting in the collection of negative energy. Zaikopath was unleashed onto the world once again, causing chaos to erupt across Gamindustri in what would be known as the "Zaikopath Incident". Once again, the Goddesses were unable to defeat it, and so Zaikopath had to be sealed once again. The fallout of this incident would also lead to the Failure Goddesses losing their Shares and becoming ghosts, untouched and left to the sands of time until the Ultra Dimension Neptune had returned them to the world^[27].

Though Share Energy in the world of Game Maker is still, at its core, positive emotions, the source of it is from the games that are created by the Makers of the world, rather than the beliefs and conscious faith in the Goddesses of the companies.

Implied Dimension[]

This dimension is not named, nor described in great detail, but is implied to exist as a separate dimension within the canonical games.

This dimension is described by the Ultra Dimension Neptune to "have an idol boom going on"^[4]. The only such dimension that would fit this description is the dimension in which Producing Perfection takes place, where the plot of the game revolves around how the Goddesses are becoming less popular as a result of idols taking the spotlight, thus they must pursue their own idol career; hence, an "idol boom". This suggests that the dimension where Producing Perfection takes place does in fact exist as a separate dimension in the series' canon.

Infinite Dimensions[]

From both the the official IFI website page and the Artisan Game Studios page for Super Neptunia RPG, it is stated that there are "infinite dimensions", and that a variation of Gamindustri resides in one of these dimensions (aka the dimension where the game takes place).

Whilst this game does not have any ties to the main timeline, thus making its events non-canon to the continuity, the game was still developed by Compile Heart (co-developed with Artisan Game Studios), meaning that, per the site's Canon page rules, this is at worst a "tertiary canon" statement - though this is most likely a "secondary canon" statement, considering that it is still supervised by Compile Heart - meaning that this can be taken into account when judging the overall cosmology of the series.

This would mean that, in general, the existence of infinite dimensions would make the multi-dimensional space a 2-A-sized, possibly 1-C space, since it's the space that contains all dimensions inside of it, with the dimensions themselves containing these nine (9) dimensional coordinates.

"The Dark Void"[]

The location referred to as "the dark void" is introduced in Neptunia: Sisters VS Sisters. It is first mentioned by Histoire, where she explains how monsters from this dark void launched attacks all around the world through a strange phenomenon, later revealed to be the Trendi Phenomenon, or the Buzzoer Phenomenon (バズール現象, Bazūru Genshō) in the Japanese version^[28].

Not much else is known about the dark void, however, this location could be referring to the space-time rift that is caused by a Trendi Phenomenon's appearance.

Timelines[]

Timelines, as a concept, are canonically introduced in Neptunia: Sisters VS Sisters. There are numerous alternate timelines that exist within Sisters VS Sisters alone, as indirectly explained by Gray Sister^[29].

Alternate timelines are spawned through the changes made in the past, which does not affect the present from which the individual traveled from. Rather, what it does is creates a new present; an alternate timeline branching from the changes made in the past, becoming a parallel universe^[30]. These new timelines are defined by the changes that caused them to split off from the original timeline.

These timelines are seemingly connected through the dimensional rifts that are caused from the time paradoxes and Trendi Phenomenon - the rift itself being a location with no concept of space^[29] - as Gray Sister was consumed by one such rift^[31], but subsequently thrown into a different timeline^[32] as she survived. The timelines also appear to encompass all Dimensions, as Gray Sister stated that time traveling and arriving at the exact desired Dimension is a difficult task^[29], which would therefore imply that timelines contain every single Dimension inside of them as well.

Should the time paradox be pushed to its limits^[32], however, all timelines that are spurred from the moment that they are branched off will fuse into one new timeline^[30], where none of the event past the moment the timelines are paradoxed will happen.

With this in mind, it can be concluded that each timeline is a 2-A, possibly 1-C structure, seeing how it encompasses all dimensions, of which there are stated to be an infinite amount of them, alongside the multi-dimensional space.

This would also mean that there are multiple of these structures within the grander cosmology of the Neptunia franchise, as alternate timelines can include those of different endings such as the Conquest Ending, Holy Sword Ending, and Normal Ending of mk2 / Re;Birth 2, the Normal Ending and "Good" Ending of Victory / Re;Birth 3, and the Bad and Ascension Endings of VII.

Conclusion / TL;DR[]

To summarize the ratings of the cosmology:

• Each legitimate dimension is a "Low 2-C, possibly 1-C" structure, as they are shown to be separate universes in their own rights through means of different dimensional coordinates, time-flow differences, different worldly laws pertaining to said dimension such as the creation of a Goddess, different histories of the Goddesses and civilizations, or otherwise statements of outright being different dimensions.
• The multi-dimensional space that contains all the dimensions inside of it is a "2-A, possibly 1-C" space, as it contains infinite dimensions in it per the Super Neptunia RPG statement.
• Each timeline is a "2-A, possibly 1-C" structure as it encompasses all dimensions as well as the multi-dimensional space that contains these dimensions.

References[]