The fifth manga series in the Toaru Majutsu no Index franchise. Its full title is Toaru Majutsu no Index Gaiden: Toaru Kagaku no Accelerator (とある魔術の禁書目録外伝 とある科学の一方通行, lit. "A Certain Magical Index Side Story: A Certain Scientific Accelerator").
Carrying the "Scientific" title of the series, it is like Toaru Kagaku no Railgun as unlike the Toaru Majutsu no Index Manga, which is an adaptation of the light novels, the Toaru Kagaku no Accelerator manga is an original side story written by Kamachi Kazuma himself. Artwork is done by Yamaji Arata and was serialized on December 27, 2013 in Monthly Comic Dengeki Daioh with its sister-series Toaru Kagaku no Railgun.
