A Certain Scientific Railgun is a manga and a spin-off of A Certain Magical Index. It is written by Kazuma Kamachi and illustrated by Motoi Fuyukawa. This spin-off focuses on Mikoto Misaka, the third most powerful student in Academy City, and tells the story of A Certain Magical Index from her point of view.

She has psychic powers that allows her to control electricity and she has the nickname “The Railgun”. In this setting, only one person thinks of themselves as a superhero, and dresses to match the attitude. The rest of the superpowered people in Index think of themselves as regular people and dress normally.