Toaru Kagaku no Railgun Manga

Toaru Kagaku no Railgun (とある科学の超電磁砲（レールガン）) or A Certain Scientific Railgun, is the second manga series that is based off the Toaru Majutsu no Index franchise. Unlike the Toaru Majutsu no Index Manga, which is an adaptation of the light lovels, the Toaru Kagaku no Railgun manga is an original side story written by Kamachi Kazuma himself. It is currently being illustrated by Fukuyawa Motoi.

An 24-episode anime series based on the first three volumes of the manga was broadcast from October 2009 to March 2010, followed by an OVA released on October 2010. A sequel to the anime series entitled Toaru Kagaku no Railgun S was green-lit, which was confirmed to cover the Sisters Arc in the original manga.

Background
The manga details the adventures of Misaka Mikoto and her friends in Academy City, and the dark underbelly within it, devoid of any devices that there is any other mysterious power other than Academy City. The events of the manga occur shortly before the start of the first Toaru Majutsu no Index light novel, and later becoming concurrent with the timeline.

The seeds of how Railgun came to be started when the future editor (Ogino) of Railgun made a request to Miki Kazuma, Kamachi Kazuma's editor, on how he wanted to have an Index manga in Dengeki Daioh. Due to the fact that the Index manga was already serialized in Monthly Shōnen Gangan, the editor asked for a Daioh to have one for the science side, specifically that of Misaka Mikoto.

The idea was well received by Miki, and after a general idea was drafted, the producers asked Kazuma to write the original concept of it. Kamachi Kazuma, at that point, was told that the manga would be using Academy City as a primary state, as such, he wrote the original draft with Shirai Kuroko as the protagonist, feeling that Mikoto was too powerful a character from who he could make an an entertaining manga. He was later corrected, and was asked to use Mikoto instead, despite having written "quite a bit". Because of this, he was forced to rethink everything from the ground up in order to use. It is unknown what would have become of the side story had Kuroko been accepted as the protagonist.

Motoi was later called up to be the artist of the manga, and started serialization in Daioh on April 2007. The first volume was later released on November 10, 2007. Seven Seas Entertainment licensed the manga in English and began releasing the series in North America starting with the first volume on June 2011. Like the rest of the printed series by Kazuma, the manga is distributed by Kadokawa Taiwan for the Chinese market, with the first volume being released on April 29, 2009.