The movie starts off after the events of Episode 3, when Kisaragi had sunk. The Mikawa Fleet (Furutaka, Aoba, Kako, Kinugasa and Tenryuu) are in the middle of Night Battle. Choukai uses Searchlight and gets medium damage, but they win in the end. A New Fleet Girl gets "dropped", emerging from the sea. It is Kisaragi. Kisaragi is brought back to the temporary base in Solomon Islands, but she is suffering from PTSD and has amnesia, unable to remember anyone from back in the anime, excluding Mutsuki...
(Source: Wikipedia)+ More
Characters & Voice Actors

Akagi
Main
Fujita, Saki
Japanese
Fubuki
Main
Uesaka, Sumire
Japanese
Kaga
Main
Iguchi, Yuka
Japanese
Kisaragi
Main
Hidaka, Rina
Japanese
Mutsuki
Main
Hidaka, Rina
Japanese
Akashi
Supporting
Taneda, Risa
JapanesePromotion Videos

Trailer Aniplus Asia ver.

Trailer

Announcement 2

Announcement 1
Recommended for you
Vexille
Movie
110m
Bluer Than Indigo: Fate - Miyuki
Special
15m
Battle Programmer Shirase
TV
12m
Blassreiter
TV
23m
Modest Heroes
Movie
50m
Dominion
OVA
36m
Guilty Crown: Lost Christmas
OVA
14m
Eon Kid
TV
24m
Space Runaway Ideon
TV
25m
Brynhildr in the Darkness
TV
23m
Aesthetica of a Rogue Hero
TV
24m
Hyper Police
TV
24m
Kurozuka
TV
23m
Lupin III: Voyage to Danger
Special
90m
Blue Comet SPT Layzner
TV
24m