When the mysterious Gate opened between the Japan and the Special Region, it marked an earthquake of political change for both worlds. For the great powers of Earth, the question of how to proceed is an enigma, especially for Japan's ally in the United States. In the Special region, the lords who once swore loyalty to the Empire must now question whether to pursue peace, or war.

The war against the Sirens has all but ended, and the Global Alliance of Azur Lane begins to break apart as Humanity once again turns their guns on one another. Human and Warship alike must find a way to survive this new war, while the scars of the old have still yet to heal.