AIKa Zero

AIKa Zero is a OVA sequel to AIKa R-16: Virgin Mission consisting of three episodes. It features new characters and two characters from Agent Aika namely Neena Hagen and Rudolf Hagen. AIKA Zero's opening and ending themes are FLYING KID and Dream Hunter.

Plot
19-year-old Aika Sumeragi is called to investigate the goings on at a private Catholic school that is run by a council group called the White Knights. In the school, the students have been mysteriously disappearing and those who have returned have no memory of the event. They discover that there are aliens who use rope-like tendrils to probe the girls, knocking them out and harvesting their energy, or possessing them to do their bidding.

Characters

 * Aika Sumeragi: The protagonist, now 19 years old.
 * Miyu Shiratori: The leader of the White Knights, and primary antagonist of the series.
 * Kana Shiraishi: Second-in-command under Miyu.
 * E.T.A.I.: Mysterious girl with some connection to aliens. Acts as Miyu's bodyguard.
 * Karen Minamino: Works at a maid cafe. Has little to no concept of personal space.
 * Eri Shinkai:Tagging along for the adventure and provider of equipment.
 * Neena:Attending the school under her brothers orders.
 * Risako Nagisa: Now back to teaching ang watching over Karen.

Episode list
Also three short specials called AIKa Zero Picture Drama were included with AIKa Zero DVD and Blu-ray release.