Sisters

Sisters is the collective term used to refer to the Misaka Mikoto clones produced from the Radio Noise Project. It is also used however to refer to the Mikoto clones from other projects, such as Misaka Worst. Each clone is considered a "sibling" of Mikoto, hence the use of the term "sisters" in reference to them.

Background
Mikoto provided a sample of her DNA to researchers at the 7th Medical Research Center of the Higuchi Pharmacies, under assumption that it would be used to assist children who were unable to use their muscles. Using her power to replicate bio-signs, she was led to believe that they could control the bio-electrical signal of the body and reroute it to a nerve signal network, meaning the children would be able to gain control of said muscles, thus allowing movement.

This was a complete fabrication, as the true purpose of using Mikoto's DNA was to create a clone of Misaka Mikoto—the 'Railgun'. Before mass production of the clones could begin, the simulation that the Tree Diagram produced showed that it was impossible to create a Level 5 clone of Mikoto despite genetic manipulation and use of the Testament. It showed that the clones' specifications reached less than 1% of that of the real Mikoto's, which was equal to that of a Level 2. However, the Level 6 Shift program – an experiment designed to make Accelerator, the strongest Level 5 in Academy City reach Level 6 reused the project. For the experiment, 20,000 clones were produced after Tree Diagram calculated that Accelerator killing Mikoto 128 times in battle, would allow him to achieve Level 6; however, since 128 Level 5 Mikoto clones could not be prepared, it was calculated by Tree Diagram that Accelerator killing 20,000 clones at Level 2-3 would achieve the same results.

Shortly before the termination of the Level 6 Shift and the Sisters project, Misaka 20001, also known Last Order, was created as a fail-safe if ever the clones went out-of-control. This makes Last Order the administrator of the Misaka Network and the superior of every other clone.

After being released from its cultivation chamber, the clone will look exactly like Mikoto though with longer hair and with the mentality to that of a newborn infant. They are later sent to a Testament machine, where information and emotions are installed into their brains. Their hair is later cut-short into a style similar to that of Mikoto, and they are possibly given missions and orders.

Will of the Misaka Network
It has been revealed that an existence that Accelerator refers to as the "Will of the Misaka Network" exists within it. Here, he speculates that it was superior to even Last Order, as she states that she left Last Order and Misaka Worst with him.

Seemingly incorporeal, the existence "fills" the network but leaves the means of external interference to the individual units. She can seemingly possess Last Order's body or that of any Sister clone with the exception of Misaka Worst. Unlike the rest of the clones in the network, she does not refer herself in the third person or describe her own speech, but instead uses escape commands like "/return". She also displays a wider range of emotions than the normal series, even making jokes like Last Order and Misaka Worst. She as well is also highly interested in Touma, and comments that she is concerned about him.

Appearance
In physical appearance, the clones all look almost identical to Mikoto, even down to their clothing –with the exception of panties – and as such, people like Touma have a hard time telling them apart from one another or even from Mikoto for that matter. In all drawn appearances, the clones' eyes are distinctly different from that of Mikoto or Last Order, seeming lifeless, though none of the characters seem to acknowledge or notice this, so it can be assumed that they might be just guidelines for the audience, as so they can differentiate the clones from Mikoto. All known sister clones, except Last Order, have a special set of goggles that they use to track electrons because unlike Mikoto they do not have that ability. The goggles are their most prominent feature and are again used to differentiate them from Mikoto.

Personality
The clones’ personalities are similar to that of Mikoto. Due to the clones emotions being suppressed, as they are unnecessary to the experiment, one would deduce that they are emotionless, as their expressions often remain the same, though they are in fact not emotionless and can still feel emotions even if they do not understand them. Because of their suppressed emotions, the clones talk in the third person narrative, describing themselves after finishing a sentence.

Initially thinking little of themselves as individuals, and not even identifying themselves as human, the clones later begin developing a sense of self and individuality after the termination of the project. For example, due to sharing the same memories, every single clone falls in love with Touma after he saves a single one of them from Accelerator. They also try to gain the upper-hand in regards to him, such as dieting, and giving him gifts.

Sisters Arc
The arc chronologically begins in the Toaru Kagaku no Railgun sidestory. Before Mikoto's discovery of the clones, rumors around Academy City began to spread about her having clones. The suspicion grew greater after Mikoto met Nunotoba Shinobu, and was confirmed by Mikoto herself that there were plans to create clones from her DNA, though much to her relief, the project seemed to have stopped before mass production after discovering that it was impossible for the clones to reach Mikoto's current level.

However, things started to turn for the worst when Mikoto discovers the existence of her clones were in fact true, and are being used for the growth of Accelerator into Level 6. After the slaying of Misaka 9982 in the hands of Accelerator and him sparing her life due to the intervention of the clones themselves, Mikoto takes it upon herself to stop the experiments, initially sabotaging the research facilities with the use of her hacking and electric abilities, she is later forced to destroy facilities personally after the management of the project has blocked her. However, because of this she is forced to do fight against the underground group, team ITEM who were hired to stop her. Even after coming victorious, and successfully sabotaging another facility involved in the experiment, her efforts were in vain, as the project was distributed were to various facilities. Mikoto later planned to manipulate the information being given by Tree Diagram, as the researchers relied on its computation to determine various things about the experiment. However, Mikoto's plans were completely destroyed after she discovers that Tree Diagram was already destroyed, and that the experiments continue on even without it.

The Toaru Majutsu no Index storyline begins after Mikoto assumed that the experiments have been halted due to her attacks, here, Touma meets Misaka 10031 and from whom Mikoto confirms that the experiments are still on-going despite her efforts. Touma later meets Misaka 10032 and bonds with her, and later through her, discovers the existence of the clones and the experiment with Accelerator. Touma later meets with an anguished Mikoto who just discovered that the Tree Diagram has been destroyed. Here, she plans on sacrificing herself by being killed by Accelerator at the first move, proving Tree Diagram wrong that she would be killed in a set number of moves. Though obviously Touma is against this, and after being electrocuted by Mikoto decides to fight Accelerator himself to prove that he is truly weak, destroying the assumption that Accelerator is the strongest esper. With the help of Mikoto and the clones who she convinced to protect Touma's dream, Accelerator is defeated and the experiment is stopped.

The clones are sent to various facilities for readjustments, as their bodies were deteriorating and their lifespans shortening, due to their accelerated growth through drugs and hormones.

Three Stories Arc
The sisters are again touched upon after the defeat of Accelerator. Here, Last Order is introduced as the 20001st clone, designed to control the Misaka Network, and asks Accelerator to help her find a research facility as so her body can become stable, as she had prematurely escaped her incubation tank. Last Order is later kidnapped by Amai Ao, who installed a virus into her – as is the reason she is escaped her tank – which would make the sister clones go haywire and out-of-control. Using his vector abilities, Accelerator is able to erase the virus from Last Order's mind, however, due to him being busy erasing the virus using his powers, Accelerator was unable to use it to defend himself and is shot by Amai Ao.

After the arc, Accelerator loses his whole calculation abilities, as well as the ability to talk properly and his ability to move. Heaven Canceler later uses the Misaka Network to compensate for half of his computational abilities, as well as the ability to talk and move.

Tree Diagram Remnant Arc
The clones quickly gain information regarding the recovery of the Remnant of the Tree Diagram. Because of this, they suspect that the Tree Diagram would be rebuilt and the Level 6 Shift would restart. Apparently their System Administrator, Last Order, is keeping her association with The Accelerator a secret from the Clones.

Despite their concerns with Misaka 10032's well-being, the clones as well as Last order, agree to have Misaka 10032 go ask for help. Here, Misaka 10032 moves out during the night to seek the aid of Kamijou Touma to help them again. Misaka 10032 indeed, was able to ask Touma for help, to which he gladly agreed to her request.

Academy City Invasion Arc
The clones remain helpless as Academy City is consumed by the chaos of Vento of the Front's attack. Here, they are completely frozen, and are only able to telepathically speak to each other through their power after Aleister Crowley activates Fuse KAZAKIRI. Here, they are forced to rely on Accelerator to aid the city, knowing full well that he is using the processing ability of their Network for his calculations.

Baggage City Arc
Following the severing of ties from Academy City by the 27 Cooperative Institutions of Academy City after the events at Hawaii, the Sister clones escaped from their housing units that the institutions provided (as it was tasked after the clones were sent to their institutions after the end of the Level 6 Shift), and erased all known traces of their DNA map in their records using their powers. It was hinted that "someone" gave battle tactics to them in their network, though it is unknown who it was.

Ichihanaran Festival Arc
After the events of the arc, Last Order returns to Accelerator only for him to discover that she has been possessed by an existence which he refers to as the "will of the whole of the Misaka Network". Here, the existence berates Accelerator for thinking that he could go the easy way out, destroy the peaceful life he has, and then go to hell once everything is put in order, by throwing himself into a fight to approach the secrets of Academy City. The existence tells that his anxiety regarding forgetting what he needs do by growing relaxed in his new life is unfounded. As he is a monster, the existence tells him that it is most comfortable for him to have an easy conflict, violence, and victory, is only naturally for him. However, the existence states that his calculation power was not given to him just so he can take the easy way out.

The existence states that he must struggle for someone's sake, struggle in the way that is most difficult, and threatens him that if he took the easy road and become a monster, then the existence will throw him into a hell several sizes larger than his imagining. The existence concludes that despite leaving Last Order and Misaka Worst, the existence is rather much interested with Touma and is concerned for his well-being as of late.

With that, the "e-mail" ends and Last Order collapses to the floor.

Magic God Othinus Arc
In the final recreation of the world by Othinus created specifically to break Touma's spirit, known as the Version_Omega world in-text, where several characters from the original world have been "saved" or have not experienced great tragedy, it is Accelerator instead who saves all 20,000 Sisters, along with Last Order and Misaka Worst after stopping the Level 6 Shift Project. The clones and Last Order are first seen in the park where Othinus left Touma after recreating the world. Here, as Othinus continues to speak to Touma in order to break his crumbling resolve, Last Order and a few of the clones appear, chasing after a paper airplane. Mikoto and Accelerator soon follow them as well. Seeing this, Touma admits that he couldn't save over 10,000 clones, and wishes he realized the events surrounding them sooner that there might have been a different option. He begins blaming himself for accepting that the incident with the Sisters have been resolved. His self-deprecation allows Othinus to continue to break Touma, with him eventually realizing that his very existence and choices may have caused great tragedy to befall people.

Later, after Touma's spirit has been finally broken and is trying to decide on how he should have himself killed, Last Order, several of the Sisters, and Misaka Worst are in the festival in the Academy City accompanied by Accelerator, Yoshikawa Kikyou, and Amai Ao. Last Order is enjoying the festival, commenting on how she has given up on trying to process all the information in front of her. A Sister then says that if she abandons any attempt to understand, they will suffer as well, and asks Last Order to try harder. The clones later become enamored by the foodstands, prompting Misaka Worst to egg them on. However, the Will of the Whole Misaka Network is affected by this change as she neither is alive nor dead just existing, twisting her form into something different. She later takes over Misaka 10031's body and stops Touma from committing suicide after falling into utter despair in the perfect world. She then takes him to Touma's student dormitory where, she explains to him that Othinus has free control over life and death, but because of her origins she free from her control. She encourages then begins trying to convince him to discard the "perfect world" and return to his original world. After pressing him he admits that it bothers him and releases all of his thoughts and feelings to her about the "perfect world" Othinus so casually created. That she might have been wrong in how she created it and saved everyone but, he would be just as wrong to return things to normal would be just as wrong. The Will however slowly convinces him that there is nothing wrong with deciding prioritizing himself just this one time and not to hide what happened saying that she'll by his side no matter what ever happens with his friends, even if it is just the two of them.

After Touma leaves, her form "peels away" from Misaka 10031 as the "perfect world" continues in crushing and twisting her, though she could have easily asked Touma to save her to get him out of his despair, she knows that he will crumble eventually if she did so.

Coronzon Arc
During the evacuation of Academy City on December 12th, the remaining clones inside the city were evacuated while concealed inside a cargo container.

Christmas Day Arc
On Christmas Day, Misaka 10032, 10039, 13570 and 19095 made a move on the hospitalized Kamijou Touma, taking him from his bed to the bath in the amenities room, with Mikoto being embarrassed to find the four of them naked around him in the bath. After the clones were sent out of the room by Shokuhou Misaki, Mikoto prevented them making any further moves on Touma from the hospital's research sector.

Daihasei Festival Arc
Kihara Gensei has Kouzaku Mitori manipulate MEMBER to find one of the Sisters so that he may be able to access the Misaka Network after he takes over Exterior, as well as restrain Misaka Mikoto for him. Upon arriving there, he swiftly forces Keitz Nokleben, the security supervisor of the Level 6 Shift, and now under the employ of Misaki up on the roof in desperation with Misaka 10032 with his group of skilled special forces. He quickly takes over Exterior, going through its complex registration protocols for usage by aligning its brainwaves with his. He quickly stuns Keitz with the power of Mental Out, and later taunts Misaki on the phone regarding one he easily took over, asking her if she heard that rumors, the Level Upper. He is entralled by Mikoto's arrival in the building, saying that it saved him the effort. With Misaki collapsing after Gensei took over her giant brain (Exterior), Gensei looks upon the still ailing Misaka 10032, and destroys the security that Misaki set-up for the Misaka Network using her powers by using her powers via Exterior. With that it shatters the security against electrical viruses, and all of the Sisters in the world are quickly infected by it.

Black electricity covers the sky as the power caused by the virus infecting the Misaka Network manifests itself through each Sister across the world. Gensei is ecstatic of the results, but notes on how the energy is nothing more than show if it doesn't have any use. Mikoto finally arrives at the rooftop, and seeing a downed Misaka 10032, demands to know what Gensei done to her. However, Gensei can only smile at her arrival, referring to Aleister's favorite hidden in the shadows of the main plan, whose power he intends to awaken using Mikoto as a vessel. Suddenly, the black lightning gathering outside gathers and jumps into Mikoto. Lightning flashes on the roof as Misaka Mikoto form changes. Kihara Gensei smiles and says that the experiments will now begin, asking if Mikoto can become a Level 6.

Radio Noise
The Sisters' ability is known as Radio Noise, a derivative or type of the Electromaster ability unique to the Sisters, ranging from Level 2-3. As they are Electromasters, they can generate at least 50,000 volts of electricity, though they are unable to track electrons like Mikoto can, and require goggles in order see them. All sister clones except Last Order, are trained in the use of military standard weapons, such as machine guns, assault rifles, sniper rifles and land mines. Their power has been described as possessing 1/20,000 of the 1,000,000,000 volts of Mikoto's Railgun: 50,000 volts of electric potential. As such, although its strength is low, it is not a power that can be made light of.

Additionally, because of their Electromaster status, the clones emit electromagnetic waves from their bodies, though as a consequence, animals such as cats which are more sensitive to such things avoid the sisters.

Misaka Network
Unique to the clones with their Radio Noise ability is the faculty to connect to the Misaka Network (ミサカネットワーク), a brainwave network formed out of their similar brainwave frequency patterns, which is similar to the Level Upper Network, in fact Kiyama Harumi used the idea of espers with the same brainwave frequency patterns from the clones to create the Level Upper, due to it's great processing potential.

With the Misaka Network, the clones can, talk in a quasi-telepathic manner, experience and share the same memories of all the other clones. This shared experiences, as well having the same powers, allows them to boost their abilities and have their faculties used more efficiently. Each clone can willingly withhold information from being passed into the network, though this is seen only after the end of the experiments, when they have already established a sort of self-identity that is separate from each other. As it is similar to the Level Upper Network, using the Misaka Network, each individual clone mind connected to the network can be used for calculating purposes. This ability was used by Heaven Canceller to help Accelerator in regaining half of his calculating ability, after being shot in the head and suffering brain damage.

Similarly, like the Level Upper Network, the Misaka Network can be used to summon an Artificial Angel. Here, Last Order can be installed a program that would force her to use the brainwave network of the Misaka clones (which renders them immobile) to help her manifest and control Fuse KAZAKIRI form of Kazakiri Hyouka, the manifestation of all of the AIM diffusions of espers in Academy City. It is also revealed that the network also functioned as a single brain that held a single will that intervened with the individuals, apparently foreshadowing the Will of the Whole Misaka Network. This will intervenes with the many physical bodies, so they don’t need to narrow their thoughts down to only one opinion.

Will of the Whole Misaka Network
Existing within the Misaka Network is the collection of all 20,001 consciousness and egos of the Sisters in the network. She is a unique existence apparently different from Hyouka and Aiwass, something that Accelerator refers to as a "third existence".

Equipment
With the exception of Last Order and Misaka Worst, each Sister is equipped with a special set of goggles that enables her to see electron beams and magnetic field lines, a F2000R Toy Soldier, and a Metal Eater MX. Furthermore, due to their ability to share experiences via their brainwave network, each Sister is capable of using any weapon that any other Sister has used.

Design evolution
The clone's design has remained static throughout all their appearances, barring characters such as Misaka 10032, and clones that are forced with different clothes due to weather.

Their designs are based off Mikoto's design, though they do not retain the light in the eyes, and blush, as it is apparent often in Mikoto's design. With the goggles, Haimura's first draft thought they were lame, and as such, changed it before drawing the illustrations. Their looks were deliberate as so the reader will not get confused when the clones are next to Mikoto.

Railgun S Character Design
In Toaru Kagaku no Railgun S, the Sister clones experience a character design change. No longer "those without light in their eyes", they instead possess a look similar to that of Mikoto, although the highlights in their eyes are colored orange instead of Mikoto's white. This design has been retained in Toaru Kagaku no Railgun T.