Mikoto Misaka is the main protagonist from Toaru Kagaku no Railgun & one of the main characters from Toaru Majutsu no Index. She is from Tokiwadai Academy and is one of Academy City's Level 5 espers, ranked number three. She is nicknamed Railgun because of her ability to control electricity.
Mikoto has light brown hair with a hair-clip on the right side of her hair and her eyes are the same color as her hair. She is also shown to be insecure about her body, feeling inferior when compared to girls with bigger bust sizes.
She wears the Tokiwadai Middle School school uniform, sporting white loose/slouch socks and brown loafers with a light brown vest sweater over a white blouse and a grey skirt. She is also known to always wear shorts under every skirt and dress she wears. This surprises an amnesiac Kamijou Touma as she is the only girl who wears boxers instead of panties.
To most people, she is considered a 'proper lady' (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 Ruiko Saten and Kazari Uiharu 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. Often times she shows a childish, competitive side and even slight tsundere tendencies along with confused affections when taunted by her rival, Touma. She can also be slightly hypocritical at times, getting angry when Touma doesn't call her by her name despite never calling him by his.
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 the force wrong and save her remaining 9968 sisters (Tree Diagram predicted that she would die in the 128th 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. She's also good at playing the violin and she teaches Uiharu how to play in the Volume 12 of the Light Novel.
Though she doesn't admit it, her mother pointed out that Mikoto is bad with House work.
Mikoto has been depicted as been quite smart as she was stated to be the 8th ranked student in Tokiwadai, a school that is meant to create world leading talents and thus deals with a very advanced curriculum. Furthermore she as been shown to easily solve problems meant for Kamijou Touma who courses a school grade higher than her, though it should be noted that Kamijou's school doesn't pursue the same Academic excellence that Tokiwadai does. Mikoto is being hit on by delinquents, when Touma Kamijou tries to save the delinquents from her (as he knows who she is and what she can do). This eventually causes her to confront Touma — even unleashing her most powerful attacks at him. Mikoto eventually caused a massive blackout throughout Academy City because of this.
Mikoto's power is known as the Railgun. She chose the ability name herself, naming it after her famous finishing move. Her ability belongs to a type of power users called Electromaster: 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.
- Railgun: Mikoto can fire metal objects at three times the speed of sound using 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 primarily uses arcade coins as her projectiles for portability, limiting her normal range to 50 meters.
- Lightning Attack Spear: 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 powerful enough to cause an 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 or Iron Sand Sword: 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.
- 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.
- Flight: Using formulas similar to those she uses for her Iron Sand sword, Mikoto can fly if she is surrounded by a large amount of atomised water vapor. She manipulated the water vapor 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.
- Defense Against Telepathic Manipulation: Mikoto has been shown to be to immune the effects of telepathic manipulation due to the electromagnetic barrier created by her AIM dispersion field.
- Mikoto Misaka appears in a PSP game of Toaru Majutsu No Index fighting game.
- Mikoto Misaka appears in Toaru Kagaku No Railgun & Cross Venus as a playable character.
- Mikoto is also about to appear in the upcoming crossover, Dengeki Bunko Fighting Climax.
- According to the interview on Kazuma Kamachi featured in "Toaru Majutsu no Index no Subete", the author states Mikoto is the one whom he want to choose as his friend among all Index characters.
- She is the winner of 2011 ISML Bishoujo tournament
- Out of all of the girls to have feelings for Touma, she is the only one yet to call Touma by his name (outside of the PSP video game and possibly in Volume 22 when she "cries" out to him).