AIKa R-16: Virgin Mission is an anime OVA series by Studio Fantasia. It is the prequel to the Agent Aika (AIKa) OVA series, also by Studio Fantasia. The series takes place 10 years before the events in Agent Aika. This series also celebrates the 10th anniversary of the original AIKa OVA. High school student Aika Sumeragi with her sharp mind and athletic body has passed the C-class Salvager test and got herself a C-class Salvager license. Despite being a sixteen year old teenager now, she is still being treated as a child by Gozo. Having finally gotten a license Aika started putting up posters offering her Salvager services. At that time her classmate and president of the Treasure Hunting Club, Eri Shingai posted a request for her. Aika gladly undertook Eri's request and boarded Eri's private cruiser. Onboard she learned about the mysterious girl called Karen who is the reason for the request. That night Aika was assaulted by high school girls and Karen was almost captured. What secret does Karen hold? Thus starts Aika's new(?) adventure..
Trial 1: Secret Game
Aika Sumeragi, a high school age C-Class salvager, is hired by class president Eri Shinkai to pilot her salvaging vessel. After introducing Aika to the treasure hunting club, and revealing coordinates hidden in a marking on fellow classmate Karen Minamino's chest, they embark on an adventure to see where it leads.
Trial 2: Peach Peach Beach
After arriving at the coordinates, Eri decides the treasure hunting club needs a break and declares that they will have a beach party on a nearby island. They are not alone, however, and Aika has to fight her teacher to protect Karen.
Trial 3: Deep Blue Girl
In the final episode of the series, Aika, Eri, and Karen find an old airport at the bottom of the ocean. After exploring the still functional facility, they finally uncover the secret to Karen's past.