Mikoto Misaka

Misaka Mikoto (御坂 美琴 Misaka Mikoto) (born May 2) is one of the main heroines 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 female character of the science side and the second main heroine of the entire series as a whole.

She is the third ranked Level 5 esper in Academy City, and has been nicknamed 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), while in the English dub she is referred to as "Bug Zapper" (or more usually, simply "Zapper"), and whenever the two meet, he usually calls her that, even after his amnesia.

Appearance
Mikoto has chestnut hair and is often seen wearing a small hair clip (firstly a rather simple one in the early stages of the story. It then was changed to one with two little flowers since the Tree Diagram Remnant Arc, specifically, from Toaru Majutsu no Index II Episode 06 in the anime, or Toaru Majutsu no Index Manga Chapter 058 in the manga). Her eyes are the same color as her hair. She is also shown to have a complex regarding her chest, 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, which surprises an amnesiac Kamijou Touma as she is the only girl who wears shorts over her panties.

Background
Mikoto is the daughter of Misaka Tabigake and Misaka Misuzu. 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 after being told that it would help people who suffer from muscular dystrophy, a fatal disease.

One year before the main story, she enrolled in Tokiwadai Middle School at the age of 12, apparently as a Level 3. Possessing a high compatibility with Tokiwadai's curriculum, Mikoto quickly grew in power, becoming a Level 5 that same April, albeit the lowest ranked at the time, and achieved her current third ranking by August. In her first year, she lost a 10,000 yen bill due to A Certain Vending Machine, probably explaining her propensity for kicking it. On July 14th, she encountered and had a brief conversation with Ibotanokikouji Kaede, who had been falsely claiming to be the Number Six, with Mikoto not taking much notice of the claim or being bothered by 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.