Elder Sister

Elder Sister (姉御) is a minor character in the A Certain Scientific Railgun sidestory. She is an Academy City high school esper of unknown level who is a leader of a group of delinquents, and is a user of the Level Upper.

Appearance
She is a tall woman who has brown hair which she ties in a small ponytail. In her first appearance she wore a blue jacket with a rose logo emblazoned on the back, in her later appearances she wears her school uniform where she prefers skirts that goes down to her ankles.

Personality
She is rude, brash, and display a little disrespect to people she does not agree with, she also does not like it when people belittle her. Even then, she respects people who can stand up to her. She also apologizes to people who have been wronged by his gang without her orders.

Background
She is a high school student who is a leader of a group of delinquents. During the height of the Level Upper incidents, she used the Level Upper along with her subordinates. Her gang also uses the JonaGarden Family Restaurant as a rendezvous point for trading Level Upper with other users.

Level Upper Arc

 * Main article:Level Upper Arc

She is first seen during Misaka Mikoto's search for Level Upper in the anime. After easily defeating her subordinates, she finds out that they tried to attack Mikoto and forces them apologize to her, she also apologizes for her gang's behaviour. However, she challenges Mikoto to a battle, wanting to avenge the defeat of her gang, she attacks Mikoto where she easily dodges her attacks and retaliates while holding herself back. This irritates her, seeing that Mikoto is not treating her seriously, Mikoto acknowledges this and uses a powerful attack in the vicinity causing a blackout in the entire city. She is later seen in the episode dumbfounded by the attack Mikoto unleashed.

She later falls unconscious as a side-effect of using Level Upper.

She later appears in the special class for users of Level Upper. Here, she often chatizes one of his subordinates named Junta for complaining too much. During the physical education part of the program, she is forced to run by Yomikawa Aiho as training, however she sees this as a form of punishment and tries to attack Aiho but is easily overpowered by her. Later in the day, she tells Saten Ruiko and her friends that the program they were in is indeed punishment and is only being covered up as training, she tells them that they were simply using other means to gain abilities and complained further about their punishment. She is confronted by Ruiko much to the worry of her friends and tells her that using Level Upper is cheating and they deserve to be punished. They stare at each other afterwards where Ruiko is seen standing her ground and although irritated at first on what Ruiko told her, she grinned and simply left her alone. In the last part of the lesson, she listens to the lecture of Tsukuyomi Komoe of how this program is not a punishment but as a way to remind them that they are able to gain their abilities through their own personal reality. After the end of the class, she is seen riding on the backseat of a blue motorcycle with her gang and after seeing, Jufuku Miho (one of the attendees of the program and also a Level Upper user) she smiles at her.

Poltergeist Arc

 * Main article:Poltergeist Arc

She is last seen in the anime resting with her gang and wearing their uniforms where they are looking at Kiyama Harumi's students' message on a blimp.

Sisters Arc

 * Main article:Sisters Arc

She is briefly seen in chapter 30 of the manga.

Ability
She displays the ability "Flux Coat" (表層融解 (フラックスコート)), which allows her to manipulate the viscosity of asphalt. When using this ability, she is able to make asphalt turn into a semi-liquidous state and also make it hard enough to protect her from an electric strike. It is unknown if she is able to do is before the use of Level Upper.

Trivia

 * Her appearance in the anime completely replaces a similar scene in the Toaru Kagaku no Railgun manga where Mikoto meets Kamijou Touma again which sets-off the beginning of Toaru Majutsu no Index. This also implies that in the anime adaptation there are two black-outs that occured in Academy City which are caused by Misaka Mikoto as a result of battle.

Quotes

 * (To Mikoto)"Quit fucking around! I haven't lost yet. If you're an Ability User, take this seriously! Your shitty electricity is no match for my stone!"
 * (To Ruiko and her friends)"Punishment. Geez. We loss consciousness, and then get forced to take these lessons. Talk about rubbing salt into wounds."
 * (To Ruiko and her friends)"Dammit, what did I do wrong anyway? What's wrong with using a simple way to raise my level?"
 * (To Ruiko)"You're pretty serious aren't you?"