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 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
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

Terra of the Left and the Document of Constantine Arc

 * Light Novels: Toaru Majutsu no Index Vol. 14
 * Manga Chapters: n/a
 * Anime Episodes: n/a

Battle Royale Arc

 * Light Novels: Toaru Majutsu no Index Vol. 15
 * Manga Chapters: n/a
 * Anime Episodes: n/a

Itsuwa and Aqua of the Back's Attack Arc

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

Relaxation Arc

 * Light Novels: Toaru Majutsu no Index Vol SS2
 * Manga Chapters: n/a
 * Anime Episodes: n/a

War in Britain Arc

 * Light Novels: Toaru Majutsu no Index Vol. 17 and Vol. 18
 * Manga Chapters: n/a
 * Anime Episodes: n/a

Dragon(≠Angel) Arc

 * Light Novels: Toaru Majutsu no Index Vol. 19
 * Manga Chapters: n/a
 * Anime Episodes: n/a

Fiamma of the Right and the World War III Arc

 * Light Novels: Toaru Majutsu no Index Vol. 20, Vol. 21 and Vol. 22
 * Manga Chapters: n/a
 * Anime Episodes: n/a

Introduction

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

Level Upper Arc
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 01, 03, 04, 06, 07, 08, 09, 10, 11, 12, 13, 14

Big Spider Arc (Anime-only Arc)
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)
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
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