Mikoto Misaka

Mikoto Misaka (御坂 美琴) is a main heroine in Toaru Majutsu no Index and the main protagonist of Toaru Kagaku no Railgun. Introduced in the first volume of the light novels, her role in the story was later expanded in the third volume as well as the release of the Toaru Kagaku no Railgun manga, making her the main heroine of the science side and the second main heroine of the series.

She is the third ranked Level 5 esper in Academy City, and is nicknamed the Railgun due to her signature move. Kamijou Touma coined the nickname Biri-Biri (ビリビリ) (a Japanese onomatopoeia imitating the sound of electricity) for her and whenever the two meet he usually calls her that, even after his amnesia.

Appearance
Mikoto and a girl with shoulder-length light brown hair, tied with a yellow peg, and dark brown eyes. Wearing a school uniform light brown, with a red ribbon on the chest.

Personality
To most people, she is considered a 'proper lady' (referred as ojou-sama or お嬢様), but in reality, she's short-tempered, prideful, and has an improper attitude with some slight tomboyish tendencies and insecurities, a fact few people know of. Despite this, she is generally friendly and easygoing, and Saten Ruiko and Uiharu Kazari comment on how they are shocked to find that compared to other Level 5's, she doesn't look down on lower-level espers at all. This is probably because she was originally a level 1 esper and became a level 5 esper through very hard work.

Often times she shows an incredibly immature and selfish side and even slight tsundere tendencies when her crush, Touma, insults her. To add to this, childishness, she has an inclination towards cute things, most specifically, Gekota and Kill Bear merchandise. She also likes frog merchandise only if it features Gekota. When she realizes that a stuffed animal another person is carrying is just a regular frog, she immediately loses all of her interest in the stuffed animal. She also has a fear of bugs, as shown in episode 6 of Toaru Kagaku no Railgun.

She has a keen sense of justice, demonstrated by her frequent involvement in the crime-fighting body, Judgment, and her resolve is unshakable as shown when she was willing to lose in a fight against Accelerator on the first move to prove the Sisters Project wrong and save her remaining 9969 sisters (Tree Diagram predicted that she would die in the 185th move). She secretly likes cute things, especially Gekota (a popular frog mascot), and is easily embarrassed. She often goes to Green Mart to read manga for free in her spare time on Mondays and Wednesdays. She's also good at playing the violin and teaches Uiharu Kazari how to play in the Volume 12 of the Light Novel. Furthermore, according to Kuroko, Mikoto naturally acts as a leader, and becomes the center of attention by everyone, yet she cannot mingle with those people regardless of being the center. She states that Mikoto is at the top and defeats her enemies, but she cannot avoid making more enemies at the same time. Moreover, she states that the most important to Onee-sama is someone she can feel on the same level as her.

Mikoto has been depicted as being quite intelligent, only natural as she is in Tokiwadai Middle School, a school that is meant to create world leading talents and thus deals with a very advanced curriculum. Furthermore she has been shown to easily solve problems meant for Kamijou Touma who courses a school rank higher than her, though it should be noted that Kamijou's school doesn't pursue the same academic excellence that Tokiwadai does.

It was showed that Mikoto had intended to take the trial enrollment into Touma's school during the Ichihanaran Festival, which further showed her interest in Touma, though this came to naught as she was interrupted by Shokuhou Misaki.

Background
Mikoto was born from Tabigake Misaka and Misuzu Misaka.

She entered Academy City in elementary age, and distinguished herself as a child prodigy, initially starting out as a Level 1 and climbing her way up to a Level 5 esper. This made her a perfect candidate for the Sisters Project, which held the intent of cloning her for military use. Mikoto willingly gave a DNA sample to the researchers of the project thinking that it would help people who didn't have the ability to control their muscles properly.

She later enrolls in Tokiwadai Middle School at the age of 12, and soon becomes a Level 5. In her first year, she lost a 10,000 yen bill due to A Certain Vending Machine, probably explaining her propensity of kicking it. In one fateful event, she saved her future friend Shirai Kuroko from a robber by using her 'Railgun' ability. Kuroko eventually enrolled at Tokiwadai as well and gained great affection for Mikoto. Mikoto later became roommates with Kuroko in Room 208 - despite Kuroko being her junior - after Kuroko 'legally' removes Mikoto's previous roommate who was supposedly ill-natured towards Mikoto. Being a Level 5 esper as well as a student with consistently high grades, Mikoto is known as Tokiwadai's Ace.

Toaru Majutsu no Index
Misaka Mikoto's role initially was that of a minor character known to Kamijou Touma before his memory loss. In her reappearance after Touma's memory loss, she acts as the main heroine along with her Sisters. Like with the Toaru Kagaku no Railgun sidestory the Sisters Arc marks a turning point for her character, which is later heavily explored in later appearances, far and few they may be, as a character that has a crush on Kamijou Touma but cannot properly express it. An example of this is her overhearing of Touma promising to Etzali that he will protect her and the world around her. Her role as such remained as is for her earlier appearances, with her getting involved little with Touma's adventures and even then completely unaware of what's truly behind the surface.

It is not until her discovery with Touma's memory loss that she tries to actively become involved with Touma. Moreover, in spite of Touma's insistence in not getting her involved, Mikoto only persists. Her crush, moreover, blossoms even more. Mikoto's character involvement in the plot was not of the greater story unfolding but with her continual association with Kamijou Touma. This finally goes to head during the climactic ending of Toaru Majutsu no Index with World War III, where she goes out of her way to go to the battlefields of Russia to find Touma and bring him back. She later fails in her goal, as Touma refuses her rescue in order to save the world. Despite being a Level 5 she is powerless to save Touma and bring him back to Academy City, though she has not given up on him as shown in Shinyaku Toaru Majutsu no Index.

Shinyaku Toaru Majutsu no Index
As an extension to her role from Toaru Majusu no Index, Misaka Mikoto continues her similarly in Shinyaku Toaru Majutsu no Index, with her constantly trying to aid Touma and the battles that he is in, making her an important supporting character. Touma eventually relents to her, and brings her along for the invasion of Hawaii. She proves her mettle, and Touma comes to trust her during battle. Much later Touma would allow her to join him if she chooses to, though doesn’t actively seek out for help. It is not until the GREMLIN invasion of Tokyo, that she and even Index finally achieve getting Touma to believe in them, with him asking them to help her save Freyja. Much later, similarly to the Will of the Whole Misaka Network, she becomes instrumental in helping Touma get rid of the emotional baggage he had felt towards the Perfect World, forcing him to look at the value of the world that they live in, the world he left behind another world for, and finally achieving bittersweet victory over him. Since most of her focus is on Touma, Mikoto doesn’t actively seek out information or knowledge regarding the magic side, simply taking Touma or the other’s word for the importance of the situation that they are in.

Toaru Kagaku no Railgun
Despite the highly different tones of the original manga and the anime adaptation, Misaka Mikoto's role in the story, as the protagonist of Toaru Kagaku no Railgun involves with her dealing with the darker elements of Academy City, sometimes with a little help from her friends.

In spite of her power as the third-ranked Level 5 of Academy City, she is continually challenged by both situations and enemies that test the limits of her character. She first gets involved in an incident with people using the Level Upper, and though she helped in stopping the incident, it foreshadowed the darker side of Academy City. The turning point is of course the Sisters Arc, where she is shown to be utterly powerless against not only the first-ranked Level 5, Accelerator, but of the greater conspiracy that surrounds Academy City, her, and her clones, the Sisters. She experiences growth, humbled by her experience, that despite her power as a Level 5 there are things she cannot solve on her own and that she needs help. Kamijou Touma, who has recently lost his memories including of her, represents this character growth in the form of a crush on him.

Even after the resolution of the Sisters, conspiracies from the Dark Side of Academy City are still brewing up to take her down.

The Third Friday of September
Apparently wanting something from the Bank, Misaka Mikoto decides to use her powers to hack into it, bypassing the security measures and defenses that the Goalkeeper, Uiharu Kazari, has implemented to stop regular hackers, under the belief that those whose job it is to secure it won't cut access to the Bank as it would be too costly. She would be indeed proven right, as Kazari refuses to cut her access to the Bank.

Seeing that her enemy is an Electromaster, and that there was no way for her to prevent such a high level intruder from accessing the Banks, and moreover with her keen desire to protect the peace of the city, Kazari proves Mikoto's predictions, as instead of cutting her access she instead decides to encrypt the entirety of the Bank, its server controls, and maintenance tools with the Omega Secret, virtually rendering the data she might get useless. Mikoto is shocked by the turn of events, and seeing that it would be too dangerous for her to access the back-ups for the Bank that she believes exists because she thinks no one would be crazy enough to encrypt the Bank using that method, Mikoto decides to withdraw, though believes that whoever encrypted the Bank would be in big trouble.

Toaru Jihanki no Fanfare
Mikoto meets up with the 7th level 5, Sogiita Gunha, and challenges him to a duel with stipulations. She uses a depowered Railgun on him, which is later caught by Gunha by the teeth. They later call it a draw, though both remarking that they would surely have lost if it was a true fight.

Toaru Majutsu no Index: Love Letter Competition
Bundled with Rainbow Spectrum Colors, the short story focuses on Kumokawa Seria's letter for Kamjou Touma, hither Misaka eavesdrops on a conversation between Tsukuyomi Komoe and Yomikawa Aiho regarding Touma's love letter. Coincidentally, the letter blows away from Komoe's possession, to which Mikoto tries to grab hold it until she is interrupted by Misaka 10032, wanting the letter for herself. Temporarily disabling Kuroko to hide the existence of her clone, Misaka 10032 confronts Misaka Mikoto for the letter, and later argue, however, the clone later begins arguing with the other clones in the network, to which Mikoto could only look bemusement. All the while, the letter blows away from them.

Toaru Majutsu no Index: Road to Endymion
Misaka Mikoto appears sporadically, failing once again to get Touma's number. She becomes a key component for the mystery surrounding Ureapaddy Exica's actions, as after the effects of the Debris Storm, her call to Kuroko redirects to Touma, which she reveals how it is used by Academy City.

Shinyaku Toaru Majutsu no Index SS
Mikoto and Kuroko are in the shopping district that Index also goes to, leading to a bunch of misunderstandings thanks in part due to Touma’s advice to Index, with Index assuming Mikoto wants Touma’s money and Kuroko becoming suspicious with Mikoto for being violent in back alleys. In the end, a truck passes by before the girls creating a draft, leading to Mikoto and Kuroko’s skirts to be blow upwards.

Seeing this, and the fact that Index has seen a handiwork of a magician in play, Index offers the money to them, to “pay-off” trouble, as Touma advised, much to Mikoto’s chagrin. They of course later decline her offer.

Toaru Majutsu no Index Movie: Miracle of Endymion
Using her meeting with her in Toaru Majutsu to Kagaku no Ensemble, Arisa calls for Mikoto to become her bodyguard as she goes to a photo-shoot at the behest of Touma. Mikoto later protects Arisa from debris as an Automaton bombs the mall they are in. She tries to aid the other people but is incapable of doing so, however, a miracle happens, and Mikoto is surprised of this. Later, Ruiko later calls her while she researches about the Orbit Portal Company, the company behind Endymion, that Arisa has been abducted.

Mikoto later visits Touma in the hospital to relay to him that she couldn't find Arisa's whereabouts as well. She later leaves after Stiyl Magnus and Tsuchimikado Motoharu arrive. When she returns, she discovers that Touma has gone, much to her chagrin.

She later arrives with Kuroko to break through Endymion that have been sealed by Ladylee Tangleroad, and is later instructed by Uiharu Kazari to break one of the explosive bolts of the Endymion in order for it to be released and prevent its collapse. She later escapes as the Endymion begins breaking away.

Toaru Kagaku no Railgun OVA
In the OVA Mikoto is tormented by the dread of someone always watching her, pushed to the edge she decides to confront the feeling herself. With the help of her friends, Mikoto discovers that the culprit is an Anti-Skill member she frequently runs into, using a device that exploits the abilities of Electromasters, making them feel that they are being watched by someone. When the culprit flees using a motorboat, Mikoto uses her Railgun to stop her.

Toaru Majutsu no Index-tan
Mikoto makes regular appearances in the bundled comedy shorts. In the first episode, she appears in reused animation cells to viewers to conserve electricity, and some such nonsense, and then saying some for other of a Japanese onomatopoeia of electricity.

In the second episode, Mikoto appears during the climactic scene of the Sisters Arc, asking Misaka 10032 for assistance to protect Touma's dream, however, she could only look in confusion, as Misaka 10032 could only blankly stare and giggle at her. In the penultimate sketch, Mikoto asks questions to a series of clones and slaps one of them when she disproves of their answers, later, they announce the making the Toaru Kagaku no Railgun anime, which she says to the audience to look forward to it.

In the third episode, Mikoto is only briefly seen in the reusage of the scenes in the Tree Diagram Remnant Arc, and interposed with Saten Ruiko doing something incredibly mundane.

In the fourth episode. in a parody of her confrontation with Musujime Awaki, she attacks the people Awaki uses to shield herself, declaring them not innocent. Take note that the people are otaku.

Toaru Majutsu no Index (PSP game)
Mikoto is a playable character in the game and able to use her Railgun and electric attacks. She also has a few melee attacks in her arsenal. Mikoto has a secret route unlockable only with a special file (or through the use of dummt files) given to players of the game.

Durarara!!


In Episode 10 of Durarara!! Erika Karisawa and Walker Yumasaki are arguing about who will become the starring heroine of the series with Walker believing it to be Biri-Biri and Erika disagreeing, believing it to be Himegami instead. Each is holding the first volume of the Railgun manga.

Ookami-san to Shichinin no Nakamatachi
Mikoto appears briefly in of Ookami-san and her Seven Companions (also produced by JC Staff Animation Studios), angrily crackling electricity and her knuckles at the audience, as a potential bride candidate for the boy millionaire Nezumi Chuutaro.

Shakugan no Shana


In Shakugan no Shana S, one Yuji's friends was wearing a T-shirt with Mikoto on it while another one wore a T-shirt with Index on it.

Dengeki Gakuen RPG: Cross of Venus
Mikoto appears as an unlockable playable character in the game. The player needs to meet certain conditions in order for her to appear. When she appears Mikoto needs to be defeated for her to join the team. As a playable character she can use several of her trademark attacks, such as the Railgun and iron sand sword.

Lunatia


Mikoto is one of the NPC characters that will assist the player in the Japanese version of the Korean Lunatia. Furthermore, within the game is a "Gekota doll" item.

Lucent Heart
The Japanese MMORPG Lucent Heart developed by Gamania Digital Entertainment disclosed that Touma, along with Index and Mikoto will be added as "selectable skins" for the players to use.

Shin Megami Tensei: IMAGINE
Mikoto appeared in the Japanese version of the online adaptation of the Shin Megami Tensei series, Shin Megami Tensei IMAGINE. She was available from January 14, 2010 to February 10, 2010. The player can accept quests from her in Third Home with a slight connection between the two series. Despite the character design of the Shin Megami Tensei series, Mikoto retained her design in the game.

Abilities
Mikoto's power is known as the Railgun (超電磁砲 (レールガン) ). She chose the ability name herself, naming it after her famous finishing move. Her ability belongs to a type of esper powers known as Electromaster (電撃使い (エレクトロマスター) ): those who can generate and manipulate electricity.

Mikoto is the most powerful Electromaster in Academy City. Her maximum output is known to be 1 billion volts. She has also demonstrated enough skill and battle knowledge to fight head on with powerful beings such as a Saint like Brunhild Eiktobel.


 * Railgun (超電磁砲</rb> (</rp>レールガン</rt>) </rp>): Mikoto can fire metal objects at three times the speed of sound by forming parallel currents on both sides of her arm with her electricity. Her railgun has a muzzle velocity of 1030 m/s (2307.2 mph), and can be fired at a rate of 8 shots per minute. She has hinted she can fire multiple coins at once creating a Rail-Shotgun, however this has never been seen. She primarily uses arcade coins as her projectiles for portability, limiting her normal range to 50 meters.
 * Lightning Attack Spear (雷撃の槍): Mikoto has the ability to generate a "spear of lightning" originating from her forehead.
 * Powerful Electromagnetic Pulse: Mikoto has the ability to create magnetic pulses that target the organs
 * Lightning Strike: Mikoto can call down real lightning using her ability regardless of season. This attack was shown to be powerful enough to cause a city-wide blackout.
 * Electromagnetism: Mikoto can use electromagnetism to attract and repel metallic materials and use it to her advantage. Examples include creating a make-shift shield out of scrap metal, walking on walls and ceilings, as well as attracting iron particles in the ground around her.
 * Whip Sword (鞭のような剣) or Iron Sand Sword (砂鉄剣): Using her magnetic powers, Mikoto can form a "whip sword" by gathering iron sand, manipulating it into a sword that she can lengthen into a whip at will. By making the sand particles of the blade vibrate, she can dramatically increase the weapon's cutting power into something resembling that of a chainsaw.
 * Cracking/Hacking: Using her electric powers she can hack any electronic device and bypass normal electronic security measures with ease. She can decode the electronic flow of information, like steal the information from a credit card's magnetic strip, as well as directly process a computer's information in binary. This skill also enables her to perform acts such as erasing herself from security footage in real time or taking control of Academy City's roving security robots. Furthermore, it is revealed in Volume 7 of New Testament that she could even use her power to take control of cars.
 * Unique Sensory Perception of Electric-type Espers: As an electromaster, Mikoto is of course able to sense electric, magnetic, and electromagnetic phenomena. She is, however, able to follow the electric and magnetic field lines using her eyes, something that normal electromasters are unable to do with their limited power.  She takes this ability one step further by analyzing the reflections of the electromagnetic waves she generates, giving her no blind spots.
 * FlightMisakawings.png: Using formulas similar to those she is using for her Iron Sand sword, Mikoto can fly if she is surrounded by a large amount of atomized water vapor. She manipulated the water vapor forming it into wings using the static electricity from interactions between particles. By using her electric power to induce electrolysis on a large body of water such as the ocean, she can obtain enough hydrogen and oxygen to use as fuel.
 * Telepathic Immunity: Mikoto has been shown to be immune to the effects of telepathic manipulation due to the electromagnetic barrier created by her AIM dispersion field.
 * Radar Sense: Mikoto can sense and release electromagnetic waves around her to enable her to see the image of the room three-dimensionally without the use of her sight.
 * Control of nerves and muscles: Perhaps a reference to her powers being applied to help those with muscular dystrophy. Mikoto is shown to be able to use her powers to take control of her muscles and nerves when they have been rendered ineffective through the use of drugs. The cost of this however is that she requires to constantly use her powers on her body, making her a walking stun gun.

Exterior-forced Misaka Network connection
During the Daihaseisai, Kihara Gensei takes over Exterior, shatters the defenses Shokuhou Misaki had set-up for the Sisters against electrical viruses, and infects them with a virus that forcibly connects the Misaka Network with Misaka Mikoto. Here, Mikoto receives a tremendous amount of power, and her appearance changes as she continues to grow in power towards Level 6. Her consciousness is also suppressed due to the external influence. According to Gensei, at 53% of the way her mind would be distorted into that of something from a different dimension, while at 100% her mind and body would be destroyed as they exceed their limits, taking Academy City with her. According to Misaki, Touma’s presence (likely referring to his Imagine Breaker) restrains her growth, while Gensei says that Imagine Breaker acting as a stimulus and Sogiita Gunha with his non-standard power would cause something extraordinary to occur. It is likely the transformations Mikoto goes through is affected by Touma and Gunha’s presence.

During the course of Mikoto being forcibly used as a subject to become a Level 6, she transforms a few times, becoming more powerful each time:
 * Initial form: Mikoto’s initial form upon engulfing the power of the Misaka Network, Mikoto’s appearance changes. Her hair becomes swept back, with a few fringes gathering together to form two horn-like appearances on her head. The sclera of her eyes also darken. The most obvious change however is the appearance of two ribbon-like objects with diamond shaped objects attached to them that hug around Mikoto’s arms. It is likely a mass of compressed energy, as Gunha would later be hit by similar things later.
 * Described by Gensei as 2% up along the path of a Level 6, already it is powerful enough to create a large electric attack that completely engulfs the already tall Windowless Building and a large area that surrounds the building, though predictably the Windowless Building is unscathed. This attack is referenced as the largest scale lightning strike ever recorded. Other features of her power include creating smaller strikes that resemble beams of energy, manipulating several chunks of metal and iron sand, and seemingly traveling through the strike of her electricity - literally “riding the lightning.”
 * First transformation: Mikoto transforms even further and her appearance chances drastically. Her horns begin transforming and hardening, forming a onion-dome shaped structure on her head, at the widest part sits something that looks like an eye. Something revolves around the tapering structure, and at the top sits a sphere, like a miniature Saturn. As for the rest of Mikoto's body, the ribbons from before have begun connecting to her body itself. Her hands and feet have tapered as well and are connected with the ribbons.
 * Under this form, Mikoto can use those ribbon like things for attack, which Gunha describes as a compressed mass of energy after hit by it. It is apparently solid enough as Gunha is also pinned down by ribbon-like objects much later. Likely, all of the powers that Mikoto displayed in her previous form is retained here and in a stronger version.
 * Second transformation: What Gensei describes as the Opening Stage, this is her final form just before she is turned back to normal. Her hair is swept back, and a complex halo appears over her head: a circle with four points on each direction, and floating at the center of it is something of rectangular shaped, tapering at both ends, with the bottom part being shorter. All of her clothes disappear. Her head down to the area of her collar bones are colored black and dotted by something resembling stars, it’s as if it was outer space or the night sky. Her hands and feet has disappeared. Her hand becoming claw-like with ribbon like protrusions, with her legs even more abstract-looking, connecting through the ribbons.
 * After Mitori seemingly defeats Kuroko, she uses her Mental Out power from Exterior and orders Mikoto to destroy the Windowless Building again. Then the ground where Mikoto is floating on turns black. Mikoto holds out her hand where she forms a large black sphere of energy. Gunha would later describe this as something from another world that cannot be understood. Mikoto would later describe it as something that she called in by her desire to crush and eliminate the parts of Academy City she doesn’t like.

Kamijou Touma
Mikoto had a crush on Touma for a long time, but only realized that she had fallen in love with him near the end of the Acqua of the Back Arc. Mikoto never calls Touma by his name, only referring to him as "you" or "idiot". Since realizing her feelings, Misaka has been willing to get involved in Touma's life, trying to rescue him during World War III, and going with him to Hawaii during the Hawaiian Invasion Arc, in order to initiate a relationship with him as a couple, however she backed up when trying to give him a ring she bought. At the end of the Hawaiian Invasion Arc, Mikoto tells Touma that she will bear his burdens with him and that he is not alone. Touma was thankful for what Mikoto said but he believed that he could not let her get wrapped up in his problems. When he returns to Academy City and is immediately caught up in a dangerous situation, it has been shown that she has accepted that Touma cannot be held back in his actions, and will support him in the endeavors he might do even if those were dangerous. She refers to it as a sign of being a "good woman", however right during Agitate Halation Arc she returned back to her former outbursts relationship towards him.

Shirai Kuroko
Shirai Kuroko is Mikoto's roommate, and best friend. Because of her high status Mikoto is alienated by most of Tokiwadai, so she values Kuroko's friendship very much. Kuroko's perverted actions towards her tend to rub her the wrong way (often resulting in the latter shocking Kuroko), she doesn't consider them anything more than an annoyance. But Misaka does care for Kuroko by saving her from danger. When Kuroko is seriously hurt by Awaki, Mikoto gets very angry with her, also for getting Kuroko involved with the problem. However, Mikoto is actually angrier at herself for getting Kuroko involved. This means then Mikoto does care about Kuroko and worries about her.

Misaka 10032
Misaka 10032 is Misaka Mikoto's clone, but Mikoto considers her and the other clones to be her younger sisters. She was created from somatic cells taken from her original's hair in order to create a clone of her. Mikoto goes to great lengths to protect 10032, along with the other clones, and was willing to die so as to end the experiment. Mikoto conscience takes on a lot of personal guilt about starting the experiment, seeing as how she had given her own DNA map of her own free will (Granted she did not know the full details of why they needed her DNA map back then.). She does, however, get jealous when 10032 tries to get close to Touma, which is shown more and more as they compete for Touma's affections.

Index
Mikoto considers Index as a rival in love. After their first meeting both fought over who would stay with Touma. Both know that Touma ends up in situations where he usually saves a girl's life and were angered at him when they found he saved the other girl's life. Also, Mikoto is embarrassed to note that Index knows more about culture than she does.

Shokuhou Misaki
Shokuhou Misaki is Misaka Mikoto's archrival. Mikoto feels very uncomfortable approaching her, and will try her best to avoid her if possible. Shokuhou Misaki represents the opposite of Mikoto (girly, manipulative, suspicious of others, and working from behind the scenes). As such, Misaka feels a big dislike towards Misaki's developed chest. Despite the animosity between them Mikoto freely admitted that she would have aided Misaki if she had simply just asked for help in the Daihasei incident with Exterior.

Meigo Arisa
Arisa chronologically first appears prior to the "Miracle of Endymion." She apparently meets Misaka Mikoto beforehand, and are apparently friendly with each other enough to have a nice chat.

Design evolution
Mikoto's design has changed little over time, only becoming more deformed to fit with the light novel format illustrations. Mikoto's design, most specifically the loose socks, is derived from the dated culture, which Haimura did as to try to capture the gaps in the trends that populate Academy City in contrast with the outside world.

Due to Mikoto's increasing prominence in the series, and due to Haimura's preference, Mikoto's hairpin changes during volume 6, to mark the change of her position in the series, this is carried over to all media adaptations. By volume 12, the deformed look has become more apparent, with Mikoto, and along with other characters, getting bigger heads, and shorter arms and legs. For her winter outfit, Haimura drawn her design to contrast with Takitsubo Rikou, her traditional look in contrast to Rikou's fancy look, as well as the concept that Mikoto just chosen clothes for winter arbitrarily without thinking.

For her appearance in the 3rd New Testament volume, Haimura had her wear the outfit hat he drew for him in Pixiv, along with Hamazura Shiage.

For her appearance in the Toaru Kagaku no Railgun manga, Haimura gave out details to Mikoto's design. From her clothes, hairstyles, up to her expressions that are common in manga.

Trivia

 * According to the interview on Kazuma Kamachi featured in "Toaru Majutsu no Index no Subete", the author states Mikoto is the one whom he would want to choose as his friend among all Index characters.
 * According to an interview her birthday is May 2, making her a Taurus ♉. Mikoto (and her clones) have blood type AB.
 * Mikoto has been ranked first on the light novel guidebook "Kono Light Novel ga Sugoi!"'s annual female character rankings for five consecutive years (2010-2014), a record achievement for any light novel character.
 * She came in first in the Toaru Sakuhin no Convention character poll of the Toaru Kaki no Campaign event.

Quotes

 * (To Touma after he negated her electrical attack, from Volume 1) : "Really, what's with that? Such a power doesn't even appear in Academy City's databank. If I am a 1-in-328,571 prodigy, then aren't you, the only one in Academy City, a 1-in-2,300,000 disaster?"
 * (To Touma who is confused as to what she's talking about, from Volume 3) : "...Hm, maybe I think I shouldn't be saying nonsense. But as long as the weak whimper, the strong will swagger... that's what I believe. Why are you different? Even here in Academy City, there are only seven Level 5s, and while each of them has the 'power' to easily twist a man's arm, just why were you chased all over town by even a street rogue's unleashed chihuahua?"
 * (While having a "fake date" with Touma, from Volume 5) : “…Oi, do you understand the situation right now? How do we look like a couple right now? Just studying and leaving the girl at the side, do you think this is male-dominant medieval Europe or something?”
 * (To Touma who is about to go to battle once again, from Volume 16) : "The feelings people go through waiting for you, have a taste of it at least once! Lay down on the hospital bed and try knowing the feeling of a person who can't do anything but watch from a safe distance! It was the same when you saved the Sisters. You told me to ask you for help, then you alone go to challenge Academy City's strongest Level 5. Why won't your own ideologies apply to yourself as well? Why are you the only one not asking for help!?"
 * (To the bomber pilot as Mikoto threatens him, from Volume 20) : “Sorry about that. I’m pretty pissed off, so I can’t guarantee that I’ll hold back next time. Take me to Russia. It’d be great if you would just do your job as you were originally supposed to.”
 * (To the pilot as she prepares to parachute down, from Volume 21) : “This isn’t an issue with how risky it is. If one side is putting all their efforts into killing a normal high school student and the other side is putting all her efforts into saving that normal high school student, which side do you want to be on? Which side could you proudly say you were on?”
 * (While grabbing on to Touma, from NT Volume 2) : "But this time, you aren't alone."
 * (To Brunhild during their battle, from NT Volume 6) : "You don’t need a good reason to save a friend. If you want to save them, then save them. …I know someone who kept saying those stupid things even when he was driven to the brink of death, and he really did save over 10,000 people in the end. And that idiot that saved so many people is trying to save someone today like always. I know I can’t stop him. No matter how much I don’t want him to do anything dangerous, seeing him off with a push to the back is the sign of a good woman!"
 * (To Touma during their fight, from NT Volume 10) : “There’s no reason to fall off the cliff while bound by meaningless principles and ideologies. If you’re reaching for the happiness you alone believe in, it’s fine to choose the best arguments for the situation. It doesn’t matter if you have to spit on your own words, as long as it all works out in the end.”