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Arc Almanac

21 Oct 2026Draft. Not yet checked against the books.

All series / A Certain Magical Index / Arc 34

Arc 34 of 66 in A Certain Magical Index

Arc 34: Acqua of the Back

In the story: Oct

Arc name chosen by Arc Almanac, because the books don’t name it.

I’ve watched through

Index I stops before this arc.

Railgun stops before this arc.

Index II stops before this arc.

The Miracle of Endymion stops before this arc.

Railgun S stops before this arc.

Seen by the end of Index III.

Accelerator stops before this arc.

Railgun T stops before this arc.

Item (episodes 1–2; airing) stops before this arc.

What happens

Acqua enters Academy City to confront Touma, placing demands on him that the Amakusa refuse to accept. Their defense draws Kanzaki into a battle against an opponent whose position in God's Right Seat makes him especially dangerous.

Where it sits

Acqua of the Back in A Certain Magical Index
FormatVolumesUnitsLanguage
Light novel — A Certain Magical IndexVol 16Prologue–epilogueJapanese
Light novel — A Certain Magical IndexVol 16Prologue–epilogueEnglish
Manga — A Certain Magical IndexVol 25, 26, 27Chapters 150–164Japanese
Manga — A Certain Magical IndexVol 25, 26, 27Chapters 150–164English
Anime — A Certain Magical IndexIndex IIISeason 3, episodes 7–9—

Draft. Not yet checked against the books. Report a wrong mapping.