Those Orange Days ...Akari, Aika, and Alice return to Aria Company after practice to find their three mentors talking, and learn they once also did combined training but have seldom all met together since becoming Primas (full undines). In flashbacks, their mentors tell the story of how Alicia and Akira as Singles hear of Orange Planet's new prodigy; when they meet a Single from Orange Planet named Athena, Akira asks about this unknown rival, but Athena is unable to answer her...