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.