I just finished the event featuring these shipgirls in Azur Lane and the story was amazing!
To sum it up, a group of shipgirls assigned to research a huge meteor in some artic sea get stuck in a submarine underwater for about a year, a year spent in a dream-like state connected to a siren(aka aliens)-made machine that was supposed to aid with the meteor's analysis... ended up trapping the girls in a dream-loop that repeat itself over and over until one of the girls almost goes insane but manages to break up from the loop and awake from the stasis - the group is ultimately rescued and brought home and treated as heroes, I guess this picture represent their parade or something.

Really good story o.o
(Better than Cowboy Bebop's story which incidentally I just finished watched today and BOY what a bore was that anime :X)