Aika R16: Virgin Mission

After receiving her C-class Salvager license, Aika Sumeragi, a 16-year-old high school student, advertises her services as a C-class Salvager by posting flyers throughout the school. Eri Shinkai, the affluent class president and founding member of the Treasure Hunting Club of Aika, hires her right away. The club launches an oceanographic trip on Eri's private cruiser after meeting Karen Minamino, a fascinating girl with an unknown past and a butterfly insignia on her left breast. The mission is to decipher the clues hidden in Karen's insignia. Risako Nagisa, the school's form teacher, tries to sabotage the trip and capture Karen, and the crew discovers a weird underwater airport with Aika's favorite Beluga submarine, raising further suspicions as they travel. As the puzzle's pieces slowly come together, Karen's world is flipped upside down as the crew discovers old technology to which Karen is the key and traces of biogenetic research.