Azur Lane: Humanity's Last Marines

Three marines from the Eurasian People's Navy are on a joint mission against the Federal Oceanian Army, which has been conducting airstrikes against the said navy's country as part of its exansionist military campaigns. Their task is to destroy an Oceanian airfield near the nation's border.

Fate seems to have other plans for them as a storm manifests and takes them to an alternat WW2 universe named 'Azur Lane'. At first, the three marines are unable to comprehend their current situation. That is, until they are caught in the crossfire between the Azur Lane and Red Axis factions.

Now stranded in this 1940s universe, the three marines are left with an uncertainty as to what their next course of action will be.

What those marines don't know is that they are humanity's last hope for the victory against the alien threat known as Sirens.