Satsujinki Series  

Satsujinki to Never End, Killer Device and Never End, Satsujinki to Deep End, Killer Queen and Deep End, Murderer Series, 殺人鬼シリーズ

In this tale, individuals referred to as "Killer Demons" possess unique abilities in the art of murder. The narratives "Satsujinki to Deep End" and "Satsujinki to Never End" detail distinct encounters between these characters and a Killer Demon.

Satsujinki to Deep End was originally submitted for, but did not win a Dengeki contest before Toaru Majutsu no Index was published. It was later published in 2004 in response to Indexs popularity.