Aika, stylized as AIKa (アイカ) or its English title Agent Aika, is an OVA miniseries consisting of 7 episodes. The series was released in Japan from 1997-1999. The anime was initially licensed by Central Park Media, but was later licensed by Bandai Entertainment.
Synopsis
A catastrophic earthquake has left Tokyo, and most of the Earth for that matter, under the sea. Aika is a salvager who retrieves various remains from the watery ruins. When Aika accepts the dangerous mission of locating and obtaining the mysterious Lagu, she discovers that she's not the only one after it.
