Nena Hagen

A catastrophic earthquake has left Tokyo, and most of Earth for that matter, under sea level. Aika is a salvager who retrieves various remains from the watery ruins. When Aika accepts the dangerous mission to locate and retrieve the mysterious Lagu, she discovers that other dangerous parties are also interested. Source: ANN

In the future — in a world mostly submerged under water — the 19-year-old Sumeragi Aika goes to college while training as an agent by assisting in Aida Gozo's salvaging business. Source: ANN Note: The first episode aired on AT-X a month before the DVD release.