Blue Submarine No. 6 (青の6号, Ao no Roku-go?) is the name of a manga series by Satoru Ozawa, which was subsequently developed into a four episode OVA series by GONZO. In the near future, the oceans have risen, causing all land at sea level to be flooded. With the expansion of the oceans, humanity has found a new enemy in Zorndyke. A war has erupted between the surface wellers and the sea dwellers, and mankind is placing all of its hopes in the new vessel Blue Submarine No. 6 and her crew. Mayumi Kino is a young, devoted pilot. Her most recent mission is to get Tetsu Hayami to rejoin the Blue Fleet. However, he refuses and angers her, so she leaves. Later, however, the two meet again under more dire circumstances and they start to work together. Even in the thick of battle, however, it becomes clear that they don't see eye to eye.
In the near future, a stagnant giant typhoon, the so called Grand Roar, suddenly appeared in the West Pacific Ocean. The typhoon changed the world's climates and Earth's appearance considerably. The rising sea levels, changing ocean currents and climates caused much damage across the world, especially in Asia. Later, the disaster was called Case Omega, and it was deeply engraved in history. Fifty years have passed since the "Grand Roar" appeared and mankind has recovered by dint of blood, sweat and toil. Re-embracing the importance of the ocean, they enter into the second Age of Discovery. However, a dark shadow lies over this Age. That shadow is the presence of organized terrorists, pirates. To cope with the threat of these pirates, private enterprises organize their own armed self-defense organizations. This story is about a female crew who embark on an escort ship of a private enterprise in order to fight the pirates.
