Index-tan is Index stripped of every ounce of dignity and placed in situations that make fun of the source material's own logic, and the voice acting commits to the bit hard enough that it loops back around to being genuine. The comedy lands because it knows exactly what fans remember about the original series and weaponizes that against them. Two episodes is all it takes to understand why this became the special people actually rewatch.

Index-tan stars in a set of short comedy pieces spun off from A Certain Magical Index. The release is a special made up of two episodes, first put out in 2009. As its comedy genre label suggests, the focus is on light humor built around the Index-tan character rather than a larger story.