Azur Lane the Animation: Aoki Kouro ni Vacances wo

Azur Lane, a combination of all the different Camps in the world, was once successful in repelling the underwater menace, the Siren. Now splintered, they must face a new threat in Red Axis, former allies who crave to wield this otherworldly Siren technology for their own nefarious desires! Who will be victorious in the never-ending war between these battleship girls!?
Source: Funimation