There were 4 factions,united to fight against an evil that came from another world,The Sirens a unknown force that came from another world,bent on destroying humanity and everything in earth,they took the oceans,one by one,pushing humanity out of the sea,to counter this threat,humanity created a solution,with the power of a strange cube,humanity made the organization,known as "Azur Lane",an organization that fought against the sirens with the beings known as shipgirls,with them,humanity fought back and pushed the sirens away from their oceans They successful pushed the sirens back and humanity took back their oceans,but due to the lack of a common enemy,Azur Lane turned on each other,splitting the factions that made it into 2 They went to war over their disagreements and fought,with humanity not knowing about it In one of the factions,known as Iron Blood,a faction that believes that power is everything,there was one ship from said factions,frozen,left,forgotten by most,freezing in cold artic temperature,they would be the one to turn the tides of war and fix the hole between everyone

After the last stand, a fleet of powerful warships are teleported into a strange world. But they soon realize that this world is also suffering from the Siren onslaught, now they find themselves separated. Will they unit with each other once again, or will the Sirens gain the upper hand capture them for testing?