Toma returns to school after summer break but is followed by Index, who thinks she won't have anything to eat for lunch while he's away at school. Arriving at school, he learns that Komoe is doing research on AIM (An Involuntary Movement), the field of power that psychics emit. When Index arrives in class, Komoe sends her away and then introduces Aisa as the new transfer student. Instead of leaving, Index runs into another transfer student, Hyoka Kazakiri, and befriends her. When Toma finds them later, Komoe catches Toma skipping the opening ceremony and Hyoka mysteriously vanishes. Aisa becomes suspicious of Hyoka, recalling her as the top student at her old school but was never seen, and warns Toma and Komoe about her. Meanwhile, Tsuchimikado meets with Aleister concerning the illegal arrival of a Necessarius mage named Sherry Cromwell in Academy City and, despite Tsuchimikado's offer to take care of Sherry discreetly to preserve the peace between Necessarius and Academy City, Aleister wants Toma to defeat her, as his involvement will help the "key" to the Sector i - Five Elements Institution. As Toma, Index, and Hyoka head to an underground mall for lunch, Kuroko finds Sherry and attacks her unsuccessfully when the latter summons a Golem. Though Kuroko is saved by Mikoto, Sherry escapes and casts a spell to send eyeballs throughout the city.