空の境界 忘却録音

January, 1999: Apprentice mage Azaka Kokutou, Mikiya's younger sister, has been ordered by her mentor, Touko Aozaki, to investigate a certain incident in which fairies steal the memories of students at Azaka's school, Reien Academy. Azaka launches an investigation with the help of Shiki. (Source: Aniplex USA)