To Aru Kagaku no AcceleratorToaru Majutsu no Kinsho Mokuroku Gaiden - to Aru Kagaku no Ippou Tsuukou, a Certain Magical Index Side Story - a Certain Scientific Accelerator, to Aru Majutsu no Index Gaiden - to Aru Kagaku no Accelerator, to Aru Majutsu no Kinsho Mokuroku Gaiden - to

A Certain Scientific Accelerator, which Accelerator is the main character. The events of the manga occur after his defeat at the hands of Kamijou Touma and the gunshot wound that he received at the hands of Amai Ao, though it is later revealed that the manga takes place prior to meeting Yomikawa Aiho.