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. It is followed by a sequel OVA series, Aika Zero.
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 gotten a C-class Salvager license. Despite being sixteen years old 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 Shinkai, 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?
- Aika Sumeragi (皇藍華), 16 
- Aika's scientist parents did experiments on her when she was younger to enhance the human body. But during the experiment a large scale earthquake occurred; every one except Aika died. At that time she was rescued by Salvager Aido Gozo. Gozo takes it upon himself to bring up Aika.
- In the future she helps Gozo in his business, but now she is a newbie C-class Salvager still in training. She is always late for school. Her behavior is somehow similar to Aida Rion, Gozo's daughter and her future "sidekick". She likes machines.
- Eri Shinkai (真海エリ), 16 
- She is the class president of Aika's class (1-A) and founder, club president of the school's Treasure Hunting Club. Eri is also a mystery fanatic and comes from a very wealthy family.
- Knowing that Aika has a Class C license, she roped Aika in to help with the investigation of Karen's mystery.
- Karen Minamino (美波野カレン), 17 
- Usually silent and seldom shows any facial expression, she talks only when necessary. On Eri's investigation, Karen's past history is unknown.
- Karen has a butterfly insignia on her left breast. The insignia on magnification is made up of minute numbers which decodes to the sentence "the gate of the truth will be opened by the sleeping butterfly" and a map coordinate, which is where the group is heading to.
- Risako Nagisa (凪紗りさこ), 26 
- A teacher of the school Aika attends. Also the teacher advisor of Treasure Hunting Club. She turned out to be an enemy, having controlled three of the students with electronic devices to attack Aika and Eri and also tried to take Karen away. Her true identity is an agent from a mysterious organization sent to observe Karen.
- Gozo Aida (相田郷造), 41 
- A Salvager that rescued Aika during the earthquake incident, brought her up and trained her in the ways of the Salvager.
- Although he is from a rich family, he works as a waiter on an Eri's private cruiser. A future Salvager and Aika admirer.
- Captain (船長)
- The captain of the cruiser "Regina Eri", the cruiser that the cast is on. He is to ensure that Eri returns safely. An excellent sniper with the M21 rifle.
- Midori, Aki, Kyoko (ミドリ, アキ, キョーコ)
- The three students controlled by Risako. Members of the Treasure Hunting Club.
- Voiced by: Nozomi Masu (Japanese), Jennifer Alyx (English),
- Voiced by: Kayo Sakata (Japanese), Laura Post (English),
- Voiced by: Mai Gotou (Japanese), Michelle Ann Dunphy (English)
- "Sailing To The Future" by Ami Koshimizu
- "Rise" by Ami Koshimizu