The world is currently experiencing isolation, all thanks to the elusive sea creatures dubbed as the "Deep Sea Fleet" by the navy, who have taken over the oceans, cutting off all countries from each other. However, the nations have decided to take a stand against the Deep Sea Fleet, and have united their resources to create a weapon that matches the power of a battleship. This weapon is called the "Fleet Girls". Will the Fleet Girls be strong enough to defeat the Deep Sea Fleet? Will the newly appointed ensign, who has just arrived at the naval base where the Fleet Girls are stationed, be able to aid in this battle? Only time will reveal as the war against the Deep Sea Fleet unravels.
