Electromaster.In Academy City, Kuroko Shirai, a member of a public moral committee group known as Judgment, finds that her senior at Tokiwadai Middle School, Mikoto Misaka, has already dispatched some thugs that were targeted, much to Kuroko's chagrin. After physical exams at school, at which Mikoto is ranked a Level-5 esper, Kuroko invites her colleague Kazari Uiharu to meet Mikoto, and Kazari decides to brings along her friend and classmate, Ruiko Saten, as well. As the four go to a crêperie, where Kazari and Ruiko are surprised to find Mikoto nothing like the snobby socialite image that they had in mind, a bank robbery takes place nearby. Kuroko uses her teleportation ability to apprehend two robbers, but a third robber attempts to kidnap a wandering kid, hurting Ruiko when she attempts to stop him. This angers Mikoto, who uses her electromagnetic powers to fire her signature railgun attack at the robber and stop his escape. With the robbers apprehended by the Anti-Skills, the city's police and security, Ruiko is thanked by everyone for her brave rescue.