In the western part of Tokyo is Academy City, so-called because 80% of its 2.3 million inhabitants are students. These students undergo a special curriculum designed to develop psychic abilities and, depending on their abilities, they are grouped into 6 categories, i.e. Level 0 (no ability) to Level 5 (super ability). Kamijou Touma is one such student. Although he is classed as a Level 0, in truth, he possesses the power known as Imagine Breaker which can cancel any and all powers. Over summer break, using his Imagine Breaker, he had first saved the nun Index from the magicians pursuing her, and then assisted the Level 5 Electro-master Misaka Mikoto in her fight against the strongest among Level 5 Accelerator. Finally, Touma saved the world by averting the magic spell Angel Fall. Now, the 2nd semester begins, and Touma will soon find himself embroiled in a battle between the practitioners of science and the practitioners of magic.