19-year-old Aika reunites with Eri and Karen to investigate the serial disappearances of school girls at St. Aero academy. Some of the girls have returned but without any memories of what has happened. While going undercover as students, they discover that the student council group called the White Knights have been abducting the students, and that they are in cahoots with an alien force that penetrates and captures the girls using rope-like tendrils of light. Aika is captured by the alien, but is rescued by Risako.