Toaru Majutsu no Index SS: Kanzaki Kaori (とある魔術の禁書目録SS -神裂火織編-?) is a story written by Kamachi Kazuma, released in parts in the limited edition DVDs and Blu-rays of the first season of Toaru Kagaku no Railgun anime. The individual parts were later collected into Toaru Majutsu no Index: Gaiten Shoku Light Novel Volume 01 alongside Toaru Majutsu no Index SS: Necessarius Special Admission Test and Toaru Majutsu no Index: Road to Endymion.
The story features Kanzaki Kaori as the protagonist, as she goes around the world and space doing missions as an agent of Necessarius. However, there is more than meets the eye as each incident she encounters is connected.
At the same time when Misaka Mikoto and Shirai Kuroko were flirting in the Academy City, a magician was running around Western Europe when she received an order from the Necessarius of Anglican Church.
The story begins when the power of the Kanzaki intersects with the first heroin commemorating swimsuit--!
- Chapter 1: The Whereabouts of the Restraints — GLEIPNIR.
- Chapter 2: When Will We Outgrow Tropical Countries? — YMIR's_ocean.
- Chapter 3: The True Meaning of Environmental Protection — RULIC_letters.
- Chapter 4: This and That About Life — ALFAR.
- Chapter 5: Marine Prison — NAGLFAR.
- Chapter 6: The Best Moment — BIFROST.
- Chapter 7: The Destination of Salvation — GUNGNIR.
- Chapter 8: The One who Teaches the Secret Rune — VALKYRIE.
- A special chapter of the Toaru Kagaku no Railgun manga was used to promote this side-story, revealing a few details about the settings and events of the five chapters.
- There are several references to Norse Mythology, especially that of the Valkyrie and legendary spear of Odin, Gungnir, is prominently featured in the story.
- Chronologically, this side story is set before the Stiyl SS.