There are two parts to the story: the first part originally aired as a radio drama in Dengeki Taishō and starts with an encounter with the mysterious self-proclaimed "former" magician by Tōma Kamijō and Index in the family restaurant after Misaka decides to go back due to urgent business.
Ada dua bagian cerita: bagian pertama ditayangkan sebagai drama radio di Dengeki Taishō dan dimulai dengan pertemuannya dengan mantan magician misterius oleh Tōma Kamijō and Index di family restaurant setelah Misaka memutuskan untuk kembali karena keperluan mendadak.