Arpeggio of Blue Steel -Ars Nova-

The extreme impacts of global warming have raised sea levels in the year 2039, leading to a significant loss of land. A fleet of formidable warships with cutting-edge weaponry appears to ensure mankind learns its lesson, triggering a crushing defeat for naval forces all around the planet. Each ship in the Fleet of Fog has a "Mental Model," a humanoid avatar that symbolizes the "Union Core," or soul, of the ship. Each model has a distinct personality, but they are all loyal to the Admiralty Code, an unidentified organization that has put in place a blockade to keep people from crossing the sea. Gunzou Chihaya, a graduate of the National Marine Academy, discovers I-401 and its Mental Model, Iona, who, for unspecified reasons, sides with humanity seventeen years after the blockade. Gunzou and his companions establish a band of privateers known as the Blue Steel in an effort to embark on a perilous expedition with the newly discovered hope of bringing about peace for humanity.