A new school term begins in Academy City. On that day, a mysterious transfer student appears on the classroom where Kamijou Touma is, a student who becomes Index's first "friend", and Misaka Mikoto meets Index for the first time. The two become stuck in unusual situations, and Kamijou continues on his streak of misfortune. While the story unfolds, Shirai Kuroko remains on the sidelines, green with jealousy. Soon, Academy City is invaded with a certain magician! "The mysterious transfer student", "friend", and a magician. On Academy City under Code Red, Kamijou Touma's story begins!
