Noire is a girl who looks in her mid-to-late teens, with a slender figure, red eyes, and long black hair. Her hair is kept tied into two pigtails with blue ribbons, and go down to her waist. Her fringe isn't kept parted and she has two bangs that go down to her chin. Her attire consists of a maid-like black top with golden trimmings and white frills around her upper arm and chest, and also reveals a certain portion of her cleavage. Her skirt is white with black trimming and is rather frilled compared to her top, and goes down to her lower-thigh.
Noire, in a word, is tsundere. She is a girl who thinks highly of herself and strives to be number one in everything she does. Noire often does and say things but tries to play it off as if there is no more meaning behind her actions. It is possible that she is a very caring person at heart but masks it with snobby, arrogant attitude in the hopes people will not see through her facade.
As Black Heart, her eyes are lime green and her hair is pure white, and goes down below her shoulders somewhat, with her fringe standing above her eyes and bangs caressing her face. Her suit is black and white in color and the mechanical appearance is much more visible. It also exposes a mild amount of her cleavage. Her sleeves are pure black, with silver patches in the bicep and tricep area, her gauntlets are black with silver protrusions on the knuckle.
Black Heart's personality remains fairly unchanged in her goddess form. The only difference is that she becomes more aggressive and competitive than before, but other than that, she's basically the same.
Beginning of the End
In the beginning, Noire and the other CPUs along with Nepgear are defeated by CFW Magic which results in them being imprisoned in the Gamindustri Graveyard for three years. When Compa and IF come to rescue them, they find their Sharicite only strong enough to help Nepgear and not the others, resulting in them having to leave Noire and the others behind.
After Nepgear, who had be rescued by Compa and IF, returns with the other CPU Candidates, she is rescued along with the other CPUs and is reunited with her sister Uni. She and the other CPUs are taken to the Planeptune Basilicom to rest after finally being free from captivity.
When Nepgear and the others go to the Gamindustri Graveyard to check out the disturbance only to be defeated by CFW Magic, Noire and the other CPUs arrive just in time and save them. It is that she and the other goddesses reveal their human forms and she admits to being tired due to the lack of shares.
Noire accompanies the party to deal with the threat of ASIC by helping them to take down CFW Brave and destroy Arfoire's Factory, defeating Underling and saving Leanbox (only for them to later learn it was distraction so that ASIC could take over Planeptune), and then helping save the CPU Candidates and Histoire by defeating CFW Trick in LAN Castle.
Noire takes her revenge on CFW Magic along with the other CPUs by defeating her which results in Arfoire reviving due to them having defeated each of the CFWs who were originally apart of her to begin with.
Evil's Fading Silhouette
Noire and the others return to the Planeptune Basilicom to discuss their next course of action. With the Arfoire now revived, their options are limited to heading to the Gamindustri Graveyard and fighting her head on.
Normal/Branch End Route
After beating her, Arfoire's vessels begin to collapse but it is soon revealed that she is not truly defeated. Vert deduces that unless they seal her away that their victory will be a loss and so the four CPUs come together and use their bodies to seal Arfoire away for good.
After beating her her vessels begin to collapse but it is soon revealed that she is not truly defeated. Arfoire makes preparations to move to another vessel and Vert deduces that unless they stop her core they will be unable to defeat Arfoire. They are left with no choice but to flee and think of another plan.
Noire and the others return to Planeptune to explain the situation to the Oracles, however during the meeting they are notified that that a member of the Four Felons has appeared in each nation demanding for everyone to worship Arfoire or they will all be killed.
After hearing about Caelus from Mina, they seek her out and request information on how to beat Arfoire. Once they obtain the information they were looking for, Neptune and her friends head back to Basilicom to report their findings before relaxing in a hot spring prepared for them by Histoire. The following day, they head out to deal with the Four Felons.
After learning what to do they all head to the Heart of the Gamindustri Graveyard for their final showdown against her perfected form DOS Arfoire. They manage to defeat her and save the world from imminent destruction. In the ending of the game, Noire is shown to be working with Uni. Uni finishes her work before Noire and points out that Noire made a mistake which leads to her having to do everything all over again.
Apocalypse: Savior's Sorrow
The party returns to the Planeptune Basilicom to discuss their next course of action. Having struggled so hard against CFW Magic, they begin to doubt their ability to beat Arfoire on their own power. Nepgear suddenly remembers the story she heard about the unused cursed sword that can only be used to defeat evil. Having no other possibilities for defeating Arfoire, the Oracle began doing research on the sword while Neptune and the others go around and ask the townspeople for information.
After finding the sword they are told they must offer the lives of CPUs to power it. Everyone is surprised and naturally refuses to use such a horrible method to defeat the Deity of Sin. Nepgear proposes that other nations pour their shares into Planeptune and allow Neptune and Nepgear to fight Arfoire; that way no one will have to die. The CPUs instantly decline, not wanting to sacrifice their nations before themselves.
Nepgear still decides to follow through with her plan and goes as far as taking the other nation's shares. In Lastation they are confronted by Noire and Uni due to taking their shares. Nepgear and Neptune are forced to fight against them and eventually Noire impales herself with the cursed sword, knowing there is no other way to save Gamindustri and because she is well aware that Neptune and Nepgear are stronger than she is
Neptune faces off against Noire, Vert, and Blanc in a game and is defeated due to them teaming up against her. Nepgear arrives with refreshments for them and Histoire comes shortly after to scold both of them; Neptune for lazing around and not properly acting as CPU, and Nepgear for enabling Neptune's behavior. Noire and the other CPUs leave and head back to their own nations, leaving the two deal with Histoire on their own. When Neptune visits Lastation, Noire had apparently locked herself up in her office to focus on work, according to Uni.
To the Present!
Black Heart, White Heart, and Green Heart of the Hyperdimension are in the middle of fighting Rei who claims to be only toying with them despite the situation looking to be in their favor. Just as Neptune, Plutia, and the candidates arrives, Black Heart and the others are defeated.
Noire has been stuck with the task of opening a hole through the barrier so people can escape. She thinks that Blanc and Vert purposely intended for this to happen to her. When she tries to get someone to switch with her, everyone ends up abandoning her.