The movie finally gives KanColle's war a shape instead of episodic scatter. Naval battles hit different when they're fighting toward something specific, and watching Fubuki carry a real weight instead of being the cheerful everygirl makes the whole thing click. If you've been waiting for the series to matter beyond pretty girls and fan service, this is where it stops playing around.
The alien Abyssal Fleet still menaces humanity, and the Kanmusu, girls who carry the spirits of Japanese warships, are all that stand in its way. Their battles are grim, and sinking is a near-certain end for them. The destroyer Kisaragi was thought to be one of those lost, until the Eighth Fleet finds her floating unconscious but alive after a successful night raid. Her odd behavior makes the others wary. Soon ships begin hearing strange voices and running into red waters that damage their gear, yet Fubuki seems untouched. As these events pile up, hard truths about the Kanmusu and the Abyssal Fleet start to come out, while the girls keep fighting to free the sea and protect the ones they love. The film is a sci-fi action story built on naval combat.