A Certain Magical Index Watch Order: Index, Railgun and Accelerator

The simplest complete A Certain Magical Index watch order is release order: Index → Railgun → Index II → The Miracle of Endymion → Railgun S → Index III → Accelerator → Railgun T. Finish each season before moving to the next title; you do not need an episode-swapping spreadsheet to begin.

There is one important trade-off: Index and Railgun S tell an overlapping storyline from different viewpoints. Release order gives you Index’s version first. If Mikoto Misaka is the reason you want to watch, the Railgun-first option may suit you better.

Railgun → Railgun S → Railgun T means Railgun Seasons 1–3. Those letters do not name later Index seasons, and Accelerator is another spin-off.

The Toaru anime release-order route

This table follows Japanese premieres, not a scene-by-scene story timeline or later dub releases. In particular, the Endymion film premiered before Railgun S, even though its disc release came afterward.

The unnumbered Index is its first season; the unlettered Railgun is that branch’s first season.

Index, Railgun and Accelerator are different branches

Index follows Touma Kamijou and the nun Index as Academy City’s science side intersects with magic. Railgun shifts the focus to esper Mikoto Misaka and her friends in the city. Accelerator centers on the esper of that name and Last Order. The spin-offs share a setting and characters, but offer different viewpoints.

The official Toaru catalogue confirms the separate titles and episode totals. Across the seven TV seasons in the first table, that is 159 episodes, plus the movie; OVAs and bonus shorts are additional. A streaming service may group the titles differently, so match the full season name rather than its menu position.

If you only want the Railgun anime

Its season sequence is Railgun → Railgun S → Railgun T. Start with the unlettered first season, not S, even if a search result happens to surface that title first.

Can you start with Railgun instead of Index?

Yes. Railgun → Railgun S is a reasonable opening if you prefer to meet Academy City through Misaka and her friends. It lets the Sisters storyline unfold from Misaka’s viewpoint before you see the shorter version in Index. Avoid summaries of that arc if you want to keep its surprises.

If you then want the wider story, watch Index and Index II, followed by Endymion → Index III → Accelerator → Railgun T. You can skip the Railgun and Railgun S rows in the release table because you have already watched them. Index adds Touma’s perspective and the magic-side story, even where events overlap. This is an alternative for your viewing preference, not an official replacement for broadcast order.

If you only want the Index seasons

Watch Index → Index II → Index III. Keep the Endymion movie identified as a film between the second and third Index seasons; do not mistake it for a replacement for Index III.

Where does The Miracle of Endymion fit?

In the release-order route, watch The Miracle of Endymion after Index II and before Railgun S.

The movie’s Japanese opening day was February 23, 2013. Railgun S began in April that year. The Endymion Blu-ray and DVD followed on August 28, which is why a list based on disc releases can put the film in a different place.

The film’s Index-tan bonus short is optional after the feature; it does not replace the movie.

When should you watch A Certain Scientific Accelerator?

For this route, watch A Certain Scientific Accelerator after Index III and before Railgun T. Accelerator’s TV anime began in 2019, between those two releases.

That is release placement, not the minimum preparation. If Accelerator is your main interest, watch the first Index season first: it introduces his connection with Last Order. You do not have to finish Index III solely to understand who the spin-off’s leads are. Keep the later release position if you are following the full-franchise route.

Where do the Railgun OVA and bonus shorts go?

Keep bonus animation separate from the TV episode counts. The first Railgun season has 24 TV episodes; its OVA is an additional release, not an unlabelled twenty-fifth episode in that main run.

These placements keep an extra beside the season or film it accompanies; they are not a scene-by-scene timeline. If you are using streaming, the extra may be in a separate specials section rather than under the regular season.

For a specific bonus, check the edition’s contents before buying. Promotional videos, music and picture dramas are outside the main route.

Choosing and following an Index watch order

Why do different watch-order lists disagree?

Check the rule behind a list: premiere order, story chronology and branch-by-branch viewing can put the same title in different places. The table here uses premieres and keeps seasons together, so you do not need to shuffle episodes between shows.

What does this order cover?

It covers Index I–III, Railgun through T, Accelerator and the Endymion movie, with the bonus releases identified above. Manga, light novels and other formats have their own labels; a new volume or spin-off announcement is not automatically another TV season to insert between these entries.

Where do ITEM and Railgun’s fourth season fit?

Toaru Anbu no ITEM is a separate spin-off, not Index IV. As of September 17, 2026, its official Japanese broadcast schedule lists an October 9, 2026 start, so it is not included among the completed seasons above.

A fourth Railgun season has been announced, but it is not one of the completed seasons in this route. Finish Railgun → S → T first; T remains Season 3. ITEM is a separate title, not a new name for Railgun Season 4 or Index IV.

Want a different long-running action series next? Our Hunter x Hunter watch order explains the choice between its two TV adaptations and optional films.