Fall 2013

In the year 2039, the drastic effects of global warming have caused sea levels to rise, resulting in major loss of land. To ensure humanity learns its lesson, a fleet of powerful warships equipped with advanced weaponry emerges, causing overwhelming defeat for naval forces throughout the world. Calling themselves the Fleet of Fog, each ship has a "Mental Model," a humanoid avatar which represents the ship's heart, its "Union Core." Each model has a different personality but all follow an unknown authority known as the Admiralty Code, who have implemented a blockade to prevent humans from traveling across the sea.

Seventeen years after the blockade, Gunzou Chihaya, a National Marine Academy alumnus, stumbles upon I-401 and its Mental Model, Iona, who sides with mankind for unknown reasons. Utilizing this newfound hope of achieving peace for humanity, Gunzou and his friends form a group of privateers, known as the Blue Steel, as they set out on a dangerous journey.

[Written by MAL Rewrite]

The story is set in December of 2199, when the streets are full of anticipation for the end of the year and the start of the new one. Amid the celebrations, word spreads that Ragna the Bloodedge, an SS-class rebel with the highest ever bounty on his head, has appeared in the 13th Hierarchical City of Kagutsuchi. The apparent aim of Ragna or the "Grim Reaper" is the destruction of the system controlling the world. To collect the bounty, a motley array of unrivaled fighters converge on Kagutsuchi.

(Source: ANN)