Toaru Majutsu no Index Wiki:Overview

Toaru Majutsu no Index is a light novel series which tells the story of a boy with an unusual gift--and curse-- and his encounters with the worlds of science and magic. Soon, he finds himself in the middle of the conflict of these worlds, primarily the Magic Cabal in one side, and Academy City on the other. The series explains the workings inside these worlds and the people who will end up working with him in his quest to save others.

Meanwhile, Toaru Kagaku no Railgun acts as a supplement to the story of the light novels, adding more information into the existing facts within Academy City introduced in Toaru Majutsu ni Index. The story focuses on third-rank Level 5 Misaka Mikoto and her own misadventures in Academy City. With Judgment member and roommate Shirai Kuroko and new friends Saten Ruiko and Uiharu Kazari, they dwell on seemingly normal lives as Misaka finds out more on the hidden side of Academy City, which is far from the utopia it's supposed to be.

Settings
The series is set in an alternate present, where part of Japan's capital Tokyo becomes a semi-independent territory called Academy City. In this city, normal students undergo a special academic program designed for them to develop esper abilities. A certain classification scheme sorts out the students according to the level of their abilities, with Power Users (a term used for students under the Power Development Curriculum) from Level 0 to 5.

At the same time, the Magic Cabal, a collective term for magicians, initiate their infiltration of the city. In this world, magicians (ruled by religious organizations like the Roman Catholic Church and the Anglican Church) are enemies with the inhabitants of Academy City, who is supervised by none other than Aleister Crowley, himself a former magician.

Toaru Majutsu no Index
Kamijou Touma, a high school student, has an encounter with a girl in nun's clothing. The girl later reveals that she's Index Prohibitorum Librorum, a girl with 103,000 grimoires in her head and a fugitive from two magicians who pursue her.

It is revealed that those two magicians are actually her guardians, named Stiyl Magnus and Kanzaki Kaori, who would require her presence to perform a memory-cleansing spell which has been performed to her before to keep the secret of the treasured books inside her head intact. They realized, though, that the ritual was merely a method to keep her from gaining any friends. Touma decides to intervene and he manages to save Index from the ceremony, at a price--his memories. When Index visits Touma in the hospital, he recalls nothing that had happened before he lost his memories. Index was on the verge of crying but Touma told her that he bluffed about it; saying that he dispelled the Feather of Light using his right hand, now known as Imagine Breaker and ends up Index biting him out of rage. Index leaves as "the Frog-Faced Doctor" enters Touma's room, revealing that he had actually lost his memories. Touma himself admits that he doesn't recall anything that had happened, but told him that there is a place in him that remembers; his heart.

He lives the next few days trying to sort out his life; without his memories, he tries to fake his experience with his friends and loved ones, which he managed to pull off. Soon, he assists Stiyl to rescue a girl named Aisa Himegami, also called "Deep Blood", and finds himself trying to save Index again (when she suspected Touma being in a another dangerous situation), this time, from its previous guardian, an alchemist named Aureolus Izzard, who has the ability to translate his thoughts to reality; Ars Magna. Stiyl reveals to Aureolus that Touma saved Index from getting her memories erased and that Aureolus's plan is pointless since Tōma had already succeeded using his Imagine Breaker. Outraged with the revelation, Aureolus turns his Ars Magna against Tōma, Stiyl, and Aisa; however, Aureolus's reality-distorting magic finds itself useless against Tōma's Imagine Breaker. When Tōma realizes that Aureolus's ability cannot alter reality, but make Aureolus's thoughts come into it, he manipulates Aureolus into changing his right arm into a dragon's head to end the fight.

The chaos that ensued due to the events involving Aureolus forces him on an unexpected vacation outside the walls of Academy City with Index. However, he realizes that amidst the quiet atmosphere lies more problems: the sudden appearance of his parents Shiina and Touya and a mysterious phenomena which leaves everyone looking like someone else. Kaori and Stiyl goes to investigate the event, which they call "Angel Fall", and with Tsuchimikado Motoharu exposing his nature as a double agent for both the sides of magic and science and a mysterious Russian girl named Misha Kruezhev, they head off to search for the cause of the event. As it turns out, Touma's father is partly responsible for "pulling down an angel from the heavens" due to feng shui and Misha is in fact possessed by the Archangel Gabriel, who has the ability to turn half the world to ash. After Tsuchimikado performs a spell which decimates the Kamijou Residence, everything returns to normal.