Mikoto Misaka | Railgun in Remnant

Misaka Mikoto 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, while in the English dub she is referred to as "Bug Zapper" and whenever the two meet, he usually calls her that, even after his amnesia.

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 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 under her skirt.

To most people, she is considered a 'proper lady.' In reality, she's short-tempered, prideful, has an improper attitude with some slightly violent, boyish tendencies, and insecurities, a fact few people know of. Despite this, she is friendly and easygoing, to the point where 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 hard work.

She often shows an incredibly immature and selfish side and displays heavy tsundere tendencies when her crush, Touma, insults her. To add to this childishness, she has a soft spot towards cute things, most specifically, Gekota and Kill Bear merchandise, and is easily embarrassed. She likes frog merchandise, but 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 has a very irrational and unexplained fear of bugs, as shown in episode 6 of Toaru Kagaku no Railgun. She can also be slightly hypocritical at times, getting angry at Touma for not calling her by her name despite never once calling him by his. While generally amicable and humble, Misaka is highly individualistic. She often prefers to be solitary and dislikes the idea of being restricted by rules and duties such as those of Judgement and Anti-Skill. She wishes to avoid endangering other people and relies on her powers to try to solve problems on her own, often times despite her better judgment.

She has a keen sense of justice, demonstrated by her frequent involvement in the crime-fighting body, Judgment, and her unshakable resolve. This is shown when she was willing to lose in a fight against Accelerator on the first move, just to prove the Sisters Project was wrong and save the remaining 9969 sisters (the Tree Diagram predicted that she would die in the 185th move). She often goes to Green Mart to read manga for free in her spare time on Mondays and Wednesdays and goes to the bookstore on the 10th of each month.[6] She's also good at playing the violin and teaches Uiharu Kazari how to play in Volume 12 of the Light Novel. Furthermore, according to Shirai 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 can defeat 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 is on the same level as her.

Mikoto is known for being very intelligent, naturally 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 be capable of solving problems intended 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.

It was shown 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.

As of December of the story's first year, following the encounter with the High Priest and a glimpse at what Touma had been facing, Mikoto's pride has been considerably damaged, seeing how far behind she was and feeling she was nothing but a burden to him. At the same time, she is desperate to catch up with Touma and be able to stand on the same stage as him so she could tell him her feelings. This has led to her personality becoming somewhat unstable and developing in a potentially dangerous direction, noted by Mass Murderer Salome and exacerbated by her acquisition of the Anti-Art Attachment.