Mikagami Nagisa

Mikagami Nagisa (水鏡 凪紗) is a student of Tokiwadai Middle School who appears in Toaru Kagaku no Railgun. She was the leader of one of Tokiwadai's three great cliques; one year before the main story.

Appearance
Mikagami has freckles, green eyes and blonde hair, tied into a shoulder length braided ponytail with a blue ribbon. She wears the Tokiwadai Middle School uniform. She also wears a flexible sports bra and bike shorts under her uniform, which can withstand a drastic expansion of her body from her ability that would damage or destroy her uniform.

Background
In her years before middle school, Mikagami was continually approached by people who sought help from her ability, to the extent that most of her free time was taken up by it. In an effort to change this, when she entered Tokiwadai, she formed a clique and made it a rule that she would only use her ability for others as a reward, in an effort to minimize people approaching her. However, she underestimated how many people cared about their appearance and were willing to join, as well as the effort they would put in to get results, to the extent that the Mikagami Clique overtook the Hasekura Clique to briefly become Tokiwadai's number one clique before being overtaken by the Sha Clique.

At some point in the past, Kadosaka Rina and Sukezawa Sena did Mikagami's hair up in her current ribbon.

At the start of Misaka Mikoto and Shokuhou Misaki's first year at Tokiwadai Middle School, Mikagami was in her third year and leader of one of Tokiwadai's 'big three' cliques. The Mikagami Clique was apparently made up of students who were mostly drawn to her oil control ability and sought her to fulfill their own desires (such as manipulating fat in their body to enhance their bust or slim them down), with Mikagami only doing this for those who contributed the most to her clique. The clique was in second place and of the three, was said to be working the hardest to get results.

Abilities
Mikagami's esper ability is Oil Direction, which allows her to manipulate a target's oil content. This includes the manipulation of fat within a human body (e.g. for purposes such as bust enhancement or slimming), which she does for those who have contributed the most to her clique. As a student of Tokiwadai Middle School, it can be presumed to be at Level 3 or 4.

Mikagami is capable of fattening and slimming her body immediately, the former being used to resist attacks and increase the weight of her own attacks,  and the latter being used for speed and mobility or to slip out of bindings when ensnared in her fat form.