Misaka Mikoto (御坂 美琴 Misaka Mikoto) (born May 2) is a main heroine 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 heroine of the science side and the second main heroine of the series.

A Certain Magical Index (とある魔術の禁書目録(インデックス) Toaru Majutsu no Indekkusu) is a Japanese light novel series written by Kazuma Kamachi and illustrated by Kiyotaka Haimura, which has been published by ASCII Media Works under their Dengeki Bunko imprint since April 2004. Yen Press have licensed the novels in North America. A manga adaptation by Chuya Kogino began serialization in Monthly Shōnen Gangan from May 2007. J.C.Staff produced two 24-episode anime series between 2008 and 2011. An animated film was released in February 2013. The anime adaptations are licensed in North America by Funimation.