Story Arcs

List of Story Arcs and their corresponding summaries, for both the Toaru Majutsu no Index main storyline and Toaru Kagaku no Railgun side story. This summary does not include story timeline.

The list also includes the number of light novel volumes, manga chapters, anime episodes and specials the story arc has.

Index Arc
The Index Arc is the first major story arc introduced in the Toaru Majutsu no Index series. The arc introduces Kamijou Touma, a young man with the mysterious power of the Imagine Breaker, who meets a mysterious nun by the name of Index which pulls him into the mysterious world of magic. This arc occurs near the end of the Level Upper Arc in the Toaru Kagaku no Railgun sidestory.
 * Light Novels: Toaru Majutsu no Index Vol. 01
 * Manga Chapters: 001, 002 , 003 , 004 , 005 , 006 , 007 , 008 , 009 , 010
 * Anime Episodes: 01, 02 , 03 , 04 , 05 , 06

Deep Blood Arc
The Deep Blood Arc is a story arc that occurs in the Toaru Majutsu no Index storyline. It introduces Himegami Aisa and her ability "Deep Blood", which is central to the plans of Aureolus Izzard, a powerful alchemist and former partner of Index.
 * Light Novels: Toaru Majutsu no Index Vol. 02
 * Manga Chapters: Not included in the Manga
 * Anime Episodes: 07, 08 , 09

Sisters Arc
The Sisters Arc is a major story arc in the Toaru Majutsu no Index universe. Originally only lasting a single volume in the light novels, it is later expanded greatly in the Toaru Kagaku no Railgun manga.

The arc focuses on the ordeals of Misaka Mikoto after discovering the existence of Radio Noise sisters that are being used in the Level 6 Shift, an experiment where they are killed as so Accelerator can achieve Level 6.
 * Light Novels: Toaru Majutsu no Index Vol. 03
 * Manga Chapters: 011, 012 , 013 , 014 , 015 , 016 , 017 , 018 , 019 , 020 , 021
 * Anime Episodes: 10, 11 , 12 , 13 , 14

Angel Fall Arc
Angel Fall Arc is a story arc that occurs in the Toaru Majutsu no Index storyline. It concerns with the activation of a world-wide spell known as Angel Fall, a spell that switches the elements, as well as the appearances of persons around the world. The most notable affect of Angel Fall is the expulsion of an angel to earth.
 * Light Novels: Toaru Majutsu no Index Vol. 04
 * Manga Chapters: Not included in the Manga
 * Anime Episodes: 15, 16 , 17

Three Stories Arc
The Three Stories Arc is a story arc that occurs in the Toaru Majutsu no Index storyline. The arc focus on three separate event that happen on August 31; two stories focuses on Touma dealing with magicians while the other focuses on Accelerator dealing with the aftermath of the Level 6 Shift, which would mark the first time Accelerator is featured as a protagonist to the science side.
 * Light Novels: Toaru Majutsu no Index Vol. 05
 * Manga Chapters: 022, 023 , 024 , 025 , 026 , 027 , 028 , 029 , 030 , 031 , 032 , 033
 * Anime Episodes: 18, 19 , 20 , II 01

Kazakiri Hyouka Arc
The Kazakiri Hyouka Arc is a story arc in the Toaru Majutsu no Index storyline. It primarily focuses on Kazakiri Hyouka, a physical manifestation of all espers AIM dispersion fields in Academy City and the key of the Imaginary Number District.
 * Light Novels: Toaru Majutsu no Index Vol. 06
 * Manga Chapters: 034, 035 , 036 , 037 , 038 , 039, 040, 041, 042, 043, 044
 * Anime Episodes: 21, 22 , 23 , 24

Orsola Aquinas Rescue Arc
The Orsola Aquinas Rescue Arc is a major story arc in Toaru Majutsu no Index storyline. It focuses on the rescue of the title character of the arc, Orsola Aquinas, a member of the Roman Catholic Church who has found a way to decipher the mysterious Book of the Law, a grimoire that is said to hold great power. The arc marks the first time Touma battle against the Roman Catholic Church, as well as the first as the first time two different Christian sects – Anglican Church (specifically Necessarius) and the Roman Catholic Church (specifically Agnese Forces) – come into conflict.
 * Light Novels: Toaru Majutsu no Index Vol. 07
 * Manga Chapters: 045
 * Anime Episodes: II 02,  II 03,  II 04,  II 05

Tree Diagram Remnant Arc
The Tree Diagram Remnant Arc is a story arc in Toaru Majutsu no Index. Focusing mostly on the point-of-view of Judgment member Shirai Kuroko, it deals with an important piece of the recently destroyed Tree Diagram, the Remnant, being stolen by Musujime Awaki a fellow teleporter, as well as Misaka Mikoto and her clones' struggle to stop the experiment from happening once again.
 * Light Novels: Toaru Majutsu no Index Vol. 08
 * Manga Chapters: n/a
 * Anime Episodes: II 06,  II 07

Daihasei Festival Arc (Index)
The Daihasei Festival Arc is a story arc in Toaru Majutsu no Index. It is September 19th, and the time has come for Academy City's annual Daihasei Festival, a sporting event that pits ability users from across the various schools of the city against one another in a series contests. For Kamijou Touma, this year's festivities have come with a twist as he finds himself having to foil a plot that could wreck the fragile balance between the worlds of science and magic.
 * Light Novels: Toaru Majutsu no Index Vol. 09 and Vol. 10
 * Manga Chapters: n/a
 * Anime Episodes: II 08, II 09, II 10, II 11, II 12, II 13

La Regina del Mare Adriatico Arc
La Regina del Mare Adriatico Arc or The Queen of the Adriatic Sea Arc is a story arc in Toaru Majutsu no Index. The arc is concerned with Kamijou Touma mysteriously winning a trip to Northern Italy despite his misfortune. Here, he is suddenly caught in another conspiracy by the Roman Catholic Church, this time regarding the mobilization of an ancient weapon against Venice – The Queen of the Adriatic Sea.
 * Light Novels: Toaru Majutsu no Index Vol. 11
 * Manga Chapters: n/a
 * Anime Episodes: II 14, II 15, II 16

Academy City Invasion Arc
The Academy Invasion Arc is a major story arc in Toaru Majutsu no Index. It features a series interrelated events occurring in Academy City during Vento of the Front's attempt to search and kill Kamijou Touma, who has now become an enemy of God and the Roman Catholic Church; and Accelerator's struggle to protect Last Order, as he fights against his former mentor Kihara Amata.

In-universe it is called the 0930 Incident, an event that would influence several other events and story arcs to come later in the series, and would be the primary trigger for the final arc of the Toaru Majutsu no Index series before New Testament. This is most notably due to the now apparent hostility between the two sides after the events of the arc as well as the acknowledgment of the existence of "magic", and the ever increasing presence of Kamijou Touma and his Imagine Breaker in magic side affairs.
 * Light Novels: Toaru Majutsu no Index Vol. 12 and Vol. 13
 * Manga Chapters: n/a
 * Anime Episodes: II 17, II 18, II 19, II 20, II 21, II 22.

Skill-Out Uprising
The Skill-Out Uprising are a series of events carried out by Komaba Ritoku's Skill-Out gang, and would have culminated in Skill-Out's disabling Academy City's communication network allowing them to attack target espers.

The plan fails after the death of Komaba Ritoku and the turning over of power of his gang to Hamazura Shiage. However, the entire purpose of the plan was later carried out by Accelerator after Ritoku's death.
 * Light Novels: Toaru Majutsu no Index Vol SS
 * Manga Chapters: n/a
 * Anime Episodes: II 23, II 24

Document of Constantine Arc
The Document of Constantine Arc is a major story arc of the Toaru Majutsu no Index series. The arc concerns with Kamijou Touma being sent to Avignon, France, in order to negate the power of the titular artfact, which is being used by the Roman Catholic Church to turn the world against Academy City. However, in order to get to the artifact, he must face Terra of the Left of God's Right Seat.
 * Light Novels: Toaru Majutsu no Index Vol. 14
 * Manga Chapters: n/a
 * Anime Episodes: n/a

Battle Royale Arc
The Battle Royale Arc is a major story arc of the Toaru Majutsu no Index series. It is the only arc known not to even feature a physical appearance of Kamijou Touma, and instead focuses on Accelerator and introduces Hamazura Shiage from the first side story volume as a major protagonist. The arc deals with the conflicts of the underground organizations of Academy City and the Level 5 espers among them, revealing number 2 Kakine Teitoku of SCHOOL, who wishes to displace Accelerator as the strongest, and the number 4 Mugino Shizuri of ITEM, who sees Kakine as her major rival.
 * Light Novels: Toaru Majutsu no Index Vol. 15
 * Manga Chapters: n/a
 * Anime Episodes: n/a

Acqua's Pursuit Arc

 * Light Novels: Toaru Majutsu no Index Vol. 16
 * Manga Chapters: n/a
 * Anime Episodes: n/a

English Civil War Arc
The English Civil War Arc is a major story arc of the Toaru Majutsu no Index series. The arc focuses on a magical conflict in the United Kingdom, as Second Princess Carissa launches a Coup d'état for the throne with the backing of the Knights of England. She is opposed by her younger sister Villian, who has the aid of Necessarius, including Index and Kamijou Touma, the two orignally in England to investigate a magical attack on the Eurotunnel.

The end of this arc, as well as the following one, would immediately seque into the final arc of the Toaru Majutsu no Index light novels. In this arc, the end of the civil war is marked with Kamijou's first confrontation with Fiamma of the Right, who had taken advantage of the chaos to steal a relic that control Index and grants him access to the grimores in her memory. This is followed by Kamijou leaving Index in the care of Necessarius as he chases after Fiamma into Russia, alone.
 * Light Novels: Toaru Majutsu no Index Vol. 17 and Vol. 18
 * Manga Chapters: n/a
 * Anime Episodes: n/a

GROUP Missions Arc
The GROUP Missions Arc is a major story arc of the Toaru Majutsu no Index series. The arc occurs in parallel to the events in the English Civil War Arc, focusing on the happenings in Academy City's dark side. It continues on from the aftermath of the Battle Royale Arc, as Accelerator and GROUP try to track down the mysterious organization known as DRAGON, while Hamazura Shiage finds himself dodging assassins, ultimately finding himself in another confrontation with Mugino Shizuri.

The end of this arc, as well as the previous one, would immediately seque into the final arc of the Toaru Majutsu no Index light novels. In this arc, Last Order falls ill after the manifestation of Aiwass, the latter later pointing Accelerator towards Russia if he wishes to cure Last Order, while Hamazura rescues Takitsubo Rikou and hijacks a plane that is programmed to go to Russia already.
 * Light Novels: Toaru Majutsu no Index Vol. 19
 * Manga Chapters: n/a
 * Anime Episodes: n/a

World War III Arc
The World War III Arc is a major story arc of the Toaru Majutsu no Index series. Notably it marks the end of the original Toaru Majutsu no Index light novels. The arc focuses on the three protagonists, Kamijou Touma, Accelerator, and Hamazura Shiage, heading deep into Russia in order to save the one they hold dear just as the entire world plunges into a Third World War. In order to save Index, Kamijou is hunting down God's Right Seat member Fiamma of the Right, the man who stole the Spiritual Device that controls Index and now has sparked a global conflict in order to fulfill his ambitions. On the advice of Aiwass, Accelerator is searching for anything involving a "different set of supernatural laws" in order to heal Last Order. Meanwhile, Hamazura is searching for a place that can cure Takitsubo Rikou of Body Crystal poisoning, as well as finding materials to blackmail Academy City with.
 * Light Novels: Toaru Majutsu no Index Vol. 20, Vol. 21 and Vol. 22
 * Manga Chapters: n/a
 * Anime Episodes: n/a

Freshmen of Darkness Arc
The Freshmen of Darkness Arc is an arc of the Toaru Majutsu no Index series. Notably it marks the beginning of the Shinyaku Toaru Majutsu no Index light novels. The arc focuses on Accelerator and Hamazura Shiage as they try to return to normal lives after fighting in World War III, only to be drawn back into the darkness of Academy City with the appearance of Kuroyoru Umidori and the Freshmen. Like the GROUP Missions Arc, Kamijou Touma only appears at the end.
 * Light Novels: New Testament Toaru Majutsu no Index Vol. 1
 * Manga Chapters: n/a
 * Anime Episodes: n/a

Homecoming Arc
The Homecoming and Explanations Arc is an arc of the Toaru Majutsu no Index series. Notably it immediately picks up where the previous arc ended, namely the defeat of Kuroyoru Umidori and the return of Kamijou Touma. The arc focuses on Leivinia Birdway, leader of the Dawn-Colored Sunlight Magic Cabal, explaining to Accelerator and Hamazura Shiage the world of magic as well as warning the three heroes of a new magical faction known as GREMLIN.
 * Light Novels: New Testament Toaru Majutsu no Index Vol. 2
 * Manga Chapters: n/a
 * Anime Episodes: n/a

Hawaii Invasion Arc
The Hawaii Invasion Arc is an arc of the Toaru Majutsu no Index series. It features the three heroes, along with Misaka Mikoto, Kuroyoru Umidori, and Misaka Worst, accompanying Leivinia Birdway to Hawaii as they confront members of GREMLIN for the first time and thwart a plot against the United States of America.
 * Light Novels: New Testament Toaru Majutsu no Index Vol. 3
 * Manga Chapters: n/a
 * Anime Episodes: n/a

Natural Selector Arc
The Natural Selector Arc is an arc of the Toaru Majutsu no Index series. It focuses on the events in Baggage City as the titular tournament becomes a city-wide warzone featuring members of GREMLIN, the Kihara family, and the tournament participants in conflict, while Kamijou Touma tries to make up for his actions in Hawaii.
 * Light Novels: New Testament Toaru Majutsu no Index Vol. 4
 * Manga Chapters: n/a
 * Anime Episodes: n/a

Introduction

 * Manga Chapters: 01, 02, 03
 * Anime Episodes: 01, 02, 04

Level Upper Arc
{C The Level Upper Arc is a story arc that occurs within the Toaru Kagaku no Railgun manga and anime. It is the first story arc that occurs within the Toaru Majutsu no Index universe. It focuses on the Level Upper, a device that is sought out after by many people in Academy City as a means to easily gain powers.
 * Manga Chapters: 01, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12, 13, 14, 15, 16, 17
 * Anime Episodes: 01, 03, 04, 06, 07, 08, 09, 10, 11, 12, 13, 14

Big Spider Arc (Anime-only Arc)
{C The Big Spider Arc is a minor story arc that occurs within the Toaru Kagaku no Railgun sidestory. It focuses on Big Spider, a faction of Skill-Out that has recently increased its attack on espers, and Konori Mii's involvement with them.
 * Manga Chapters: Not included in the Manga
 * Anime Episodes: 15, 16

Poltergeist Arc (Anime-only Arc)
{C The Poltergeist Arc is a story arc that occurs within the Toaru Kagaku Railgun sidestory. It focuses on the series of earthquakes that are happening all around Academy City, which are called Poltergeist.
 * Manga Chapters: Not included in the Manga
 * Anime Episodes: 17, 18, 19, 20, 21, 22, 23, 24

Sisters Arc
{C The Sisters Arc is a major story arc in the Toaru Majutsu no Index universe. Originally only lasting a single volume in the light novels, it is later expanded greatly in the Toaru Kagaku no Railgun manga.

The arc focuses on the ordeals of Misaka Mikoto after discovering the existence Radio Noise sisters that are being used in the Level 6 Shift, an experiment where they are killed as so Accelerator can achieve Level 6.
 * Manga Chapters: 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39
 * Anime Episodes: Not included in the anime adaptation

Tokiwadai Factions Arc
The Tokiwadai Factions Arc is a story arc that takes place roughly after Kongou Mitsuko's transfer into Tokiwadai Middle School.

The "Ace of Tokiwadai", Misaka Mikoto, finally meets the fifth Level 5 named Shokuhou Misaki, and a tension forms between their factions and the two Level 5s.
 * Manga Chapters: 40, 41
 * Anime Episodes: Not included in the anime adaptation

Daihasei Festival Arc (Railgun)
The Daihasei Festival Arc (Railgun) is a story arc that shows the actual events of the Daihaseisai Festival.
 * Manga Chapters: 43, 44, 45
 * Anime Episodes: Not included in the anime adaptation