In a city of espers and science, a boy with a unique ability shelters a girl carrying forbidden magical knowledge, pulling both worlds into conflict.
Plus 3 optional extras and 1 upcoming title.
8 titles · 159 episodes + 1 movie · ~64.5 hours
Watch the main Index seasons in order and slot each Railgun season in at the point where its story connects, rather than saving the spin-offs for the end. Accelerator goes between Index and Index II, the film goes after Index II, and Railgun T goes before Index III. The three bonus episodes sit at the end as optional extras.
Start here. This season introduces Academy City, the esper ranking system, and the magic side of the setting. Episodes 10 to 14 cover the Sisters arc, which Railgun S then retells at much greater length.
The first Railgun season follows Mikoto Misaka and her friends. Its opening arc begins earlier in the story than Index does, and Index's first episodes fall around the fourteenth episode here.
Railgun S covers the Sisters arc from Misaka's side, running in parallel with episodes 10 to 14 of the first Index season. It gives the arc far more room than Index does, so watching it while those episodes are still fresh works best.
This 12-episode spin-off follows Accelerator and Last Order, continuing directly from where the first Index season leaves that character. It sits before the second episode of Index II in the timeline.
The main story continues, and the middle of the season covers the Daihasei Festival, which Railgun T also covers from Misaka's side. Watching this before Railgun T matters because an event shown only here is referenced in both Railgun T and the film.
This feature film takes place shortly after the seventh episode of Index II and tells a self-contained story built around a new character. Nothing in it carries over into Index III.
Railgun T opens with the Daihasei Festival, the same event covered in the middle of Index II, then moves into the Dream Ranker arc. Its 25 episodes make it the longest Railgun season.
⚠ The later part of the Dream Ranker arc takes place after the opening episodes of Index III, so this season and Index III overlap at the end.
The third Index season runs 26 episodes and brings the magic and science sides into open conflict. It assumes familiarity with the cast built up across the earlier seasons.
A 34-minute Railgun OVA set after the Level Upper arc, following a new urban-legend case. It stands apart from the main plot.
⚠ The Railgun bonus episodes are not consistently available on English-language streaming services in the way the main seasons are.
A short beach episode bundled with the Railgun official visual book and numbered as episode 13'. It runs only a few minutes and carries no story weight.
A six-minute slice-of-life episode released with the Railgun S official visual book. It sits inside the Railgun S timeframe.
A spin-off centred on ITEM, the four-girl unit from Academy City's dark side who appear in the main story. J.C.Staff is producing it with Tatsuyuki Nagai, who directed the Railgun seasons.
⚠ This series begins broadcasting on October 9, 2026, so it cannot be watched yet, and where it falls in the timeline is not confirmed.
Three threads run at once in this franchise: the main Index story, Railgun following Mikoto Misaka, and Accelerator. They share the same city and, in several cases, the same events told from a different side. The order here places each spin-off where its story actually connects.
Railgun's first season begins earlier in the story than Index does, but Index is the entry point that explains the world, so it comes first here. Railgun S is placed straight after it because the two cover the Sisters arc together — Railgun S runs in parallel with episodes 10 to 14 of Index and tells that arc in far more detail. Accelerator follows, since it picks up the thread Index leaves hanging with that character.
Index II comes next, then the Endymion film, which takes place shortly after the seventh episode of that season. Railgun T opens with the Daihasei Festival, the same event covered in the middle of Index II, so it belongs here rather than later. Index III closes the main story.
The two Railgun OVAs and the Railgun S bonus episode are short side pieces with no bearing on the plot, so they are grouped at the end. The ITEM spin-off has not aired yet.
A Certain Magical Index and Railgun has 7 seasons and 1 film in the main run — 159 episodes altogether.
| Title | Type | Episodes | Aired |
|---|---|---|---|
| A Certain Magical Index | TV Series | 24 episodes | October 2008 |
| A Certain Scientific Railgun | TV Series | 24 episodes | October 2009 |
| A Certain Scientific Railgun S | TV Series | 24 episodes | April 2013 |
| A Certain Scientific Accelerator | TV Series | 12 episodes | July 2019 |
| A Certain Magical Index II | TV Series | 24 episodes | October 2010 |
| A Certain Magical Index: The Miracle of Endymion | Movie | February 2013 | |
| A Certain Scientific Railgun T | TV Series | 25 episodes | January 2020 |
| A Certain Magical Index III | TV Series | 26 episodes | October 2018 |
| Title | Type | Episodes | Aired |
|---|---|---|---|
| Toaru Kagaku no Railgun: Misaka-san wa Ima Chuumoku no Mato Desukara | OVA | 1 episode | September 2010 |
| Toaru Kagaku no Railgun: Entenka no Satsuei Model mo Raku ja Arimasen wa ne. | OVA | 1 episode | July 2010 |
| A Certain Scientific Railgun S: All the Important Things I Learned in a Bathhouse | OVA | 1 episode | March 2014 |
| Title | Type | Episodes | Aired |
|---|---|---|---|
| Toaru Anbu no ITEM | TV Series | — | October 2026 |
8 titles · 159 episodes + 1 movie · ~64.5 hours
Where each part of the anime lines up with the source, so you know where to pick up reading.
Only spin-offs that tie into the main story are listed here — anthologies, fan books and the like are left out.
Two threads pick up where the anime stops. The Index anime adapted all 22 volumes of Old Testament, so the story continues in New Testament volume 1 — a separate 23-volume series that Yen Press is publishing in English, followed by the still-running Genesis Testament, which has no English edition. Railgun T stopped at chapter 97, the end of the Dream Ranker arc, so the Railgun manga continues from chapter 98 in volume 14 with the Jailbreaker arc. That manga finished at chapter 170 across 20 volumes in 2026, and the announced fourth Railgun season is expected to pick up from there. Accelerator is the odd one out: its anime covered only the Necromancer arc, volumes 1 to 7, and the Nectar arc that completes the 12-volume manga has never been animated.
Start with the first season of A Certain Magical Index. Railgun's first season actually begins earlier in the story, but Index is what explains Academy City, the esper ranking system, and the magic side of the setting, so it is the cleaner entry point.
Neither: watch it right after the first Index season. Railgun S covers the Sisters arc, which Index tells across episodes 10 to 14 of season one, not in season two. Railgun S gives that arc sixteen episodes instead of five, so watching it while the Index version is still fresh works best.
After the first Index season and before Index II. The spin-off picks up Accelerator's story from where season one leaves him, and its events take place before the second episode of Index II. It is skippable if you only want the main plot, but it is a full 12-episode series rather than a side story.
No. Railgun T opens with the Daihasei Festival, the same event covered in the middle of Index II, so Index II is the season you need first. Only the final stretch of Railgun T's Dream Ranker arc reaches past the opening episodes of Index III.
It is optional. The film takes place shortly after the seventh episode of Index II and tells a self-contained story around a new character, and nothing in it carries into Index III. Watch it if you want more of the cast; skip it without hesitation if you are following the main plot.
Yes. The Index seasons never require knowledge from Railgun. What you lose is detail: Railgun spends far longer on events Index covers in a few episodes, and Misaka becomes a major figure in the main story by Index III, so her own series makes that development feel earned.
Those are parody shorts bundled with the Blu-ray and DVD releases, with the cast redrawn in chibi form spoofing scenes from the season they came with. They sit outside the story entirely, which is why they are not in the orders above. The three bonus episodes that are listed are ordinary episodes in tone and setting.
Crunchyroll carries all three Index seasons, all three Railgun seasons, Accelerator, and the Endymion film, with English dubs available for the main seasons. The short bonus episodes are the exception and are harder to find legally in English.
Yes, two things. Toaru Anbu no ITEM starts broadcasting on October 9, 2026, following the four-girl ITEM unit from Academy City's dark side. A fourth Railgun season has also been announced, but no broadcast window has been given for it yet.
