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.

The arc marks the 2nd time the Roman Catholic Church acts as the primary antagonist for Touma, it involves the church allowing Lidvia Lorenzetti to take over Academy City for the benefit of the church using the Croce di Pietro.