The following is a list of characters and tropes that apply to them in Manga/ArpeggioOfBlueSteel. Do note that TheOtherDarrin is in full effect, as the drama CD and anime uses an entirely different set of voice actors. Note that due to the anime diverging from the manga's storyline, some characters' tropes will be a mix from either media.


!Blue Steel

The main characters. On paper an [[Main/PrivateMilitaryContractors independent firm]] that also does some work for the Japanese government, at the beginning of the series Blue Steel is the only force that has a real chance at striking back against the Fog Fleet blockade of the Japanese islands. They are eventually hired by the Central government to deliver the blueprint of a weapon that might finally turn the tide in humanity's war against the Fog to the only country still capable of producing it in the numbers needed: the United States of America.

Commanded by Gunzou Chihaya, and manned by some of his classmates from the Maritime Institute, Blue Steel's ability to fight the Fog Fleet on (somewhat) even terms is mostly due to the fact that it has its own Fog ship under its disposal: the renegade Fog submarine I-401, Iona, who follows Gunzou for reasons even she herself isn't quite sure of.

[[spoiler:Initially just composed of Iona, Blue Steel becomes a fleet once Hyuuga and Takao switch sides, but only Takao has a ship to contribute. In the ''Ars Nova'' anime Haruna and Kirishima also end up joining]].

[[folder:Members of Blue Steel]]

!!Gunzou Chihaya
[[caption-width-right:200:Gunzou, as he appears in Ars Nova.]]
->Voiced by: Creator/JunFukuyama (Drama CD), Creator/KazuyukiOkitsu (Anime)

The Captain of I-401, and he makes most of the tactical decisions of Blue Fleet in general.

* BadassInANiceSuit: He generally wears a primarily black suit and red shirt when meeting with clients. In ''Ars Nova'' he wears the suit all the time.
* BatmanGambit: Gunzou's plan to defeat Kongou's fleet in the manga required Kongou to behave as predicted in order to fall into the trap. It works, but the real genius of the plan was in the way our heroes kept limiting Kongou's options over successive encounters, increasing the likelihood Kongou would fall for it.
* TheCaptain
* ChickMagnet: Both human girls and Fog ships are attracted to him, though (probably) for different reasons.
* ChildProdigy: He was one of the top students in his class back when he was studying to join the navy.
* CombatPragmatist: He's willing to do whatever it takes to win a battle. Considering his opponents are nigh-invulnerable warships who gave humans a CurbStompBattle they still haven't recovered from, it's not surprising he's forced to think outside the box with I-401.
* DesperatelyLookingForAPurposeInLife: The revelation that his father was a traitor and losing his childhood friend Amaha Kotono in a fire causes him to become this until he meets Iona.
* DisappearedDad: His dad, a war hero who captured the I-401 during the final naval battle between the UN Fleet against the Fog Fleet, was presumed dead after leaving Japan in I-401 which later returned without it's crew. However, two years before the series began, Gunzou learns not only is his father and his crew alive but they defected to the Fog Fleet.
* {{Expy}}: With his good looks, daring strategic mind, and [[Creator/JunFukuyama identical voice]] (not to mention possessing a MysteriousWaif), drawing comparisons between Gunzou and [[Anime/CodeGeass Lelouch]] is practically inevitable.
* IntelligenceEqualsIsolation: At first, during the academy. He still has trouble relating to people but is surprisingly comfortable speaking with Fog Mental Models.
* ObliviousToLove: It's doubtful that he had any idea he had two girls swooning over him during school. One still is, the other [[spoiler:died in a terrible fire... ''[[NeverFoundTheBody maybe]]'']]
* RedBaron: Called the "Battleship Killer" and "Route Holder" in chapter one.
* TheParagonAlwaysRebels: While not exactly top of the class, he qualifies for this in the merit of always being in the top three at school and is quite a decent captain even compared with those with more experience. End result? Deserted the military, taking a few of their most talented personnel with him, and starts work as a mercenary.
* TheStrategist: He comes up with some rather unique tactics during combat to win against his opponents.
* XanatosSpeedChess: Routinely changes plans on the fly based on new information or depending on how event play out. This ability is what makes Blue Steel, and himself in particular, such a threat to the Fleet of Fog.

[[caption-width-right:200:Iona, as she appears in Ars Nova Cadenza]]

->Voiced by: Creator/AoiYuuki (Drama CD), Creator/MaiFuchigami (Anime)

A Fog ship somehow captured by humans in the Great Naval Battle seventeen years ago. While her origins are undoubtedly of the Fog fleet, she has no idea what her purpose was, other than to find and obey Gunzou Chihaya.
* AdaptationDyeJob: She has white hair in the manga, while it has more of a blueish tint to it in the anime.
* AdaptationPersonalityChange[=/=]CharacterExaggeration: Iona in the Ars Nova continuity is more of an EmotionlessGirl and acts far mechanical on the whole. Compare this to Iona in the manga, who is not only more expressive (to the point that she even has hobbies), has a personality that's downright sarcastic at times.
* AmnesiacHero: She only remembers one order, which was to obey Gunzou Chihaya. This served extremely useful for the humans, who are finally able to fight back against the Fog ships for the first time since their appearance.
* AttackDrone: [[spoiler:Uses three remotely-controlled ''airplanes'' to torpedo Kongou in the manga.]]
* BarbieDollAnatomy: During her introduction to Gunzou in the manga, Iona pretty much featured this during her NakedFirstImpression. Justified as we see her part-way through forming her body and the only part that's finished is her face.
* EmotionlessGirl: In the anime.
* LittleMissSnarker: Iona in the manga. At this point, Takao, Hyuuga, and even Ashigara and Hagurou, have been on the receiving end of her snark.
* IAmWho: In both the anime and the manga, there are enough hints that Iona ''isn't'' simply a rogue Fog submarine, though both differ in the details: [[spoiler:the anime points to Iona being an avatar of the Admiralty Code, the architect of the Fog Fleet, while the manga instead hints that she's the Joint Tactical Network itself.]]
** ''Cadenza'' lays to rest what Iona really is, as far as the ''Ars Nova'' continuity is concerned: [[spoiler:she's the Yamato. Or rather, a back-up fragment of Yamato's personality, which was saved into the I-401's union core as Yamato was sunk by Musashi.]]
* IconicOutfit: For both the anime AND the manga.
** Anime: Her Blue Steel uniform, which is composed of a blue sailor blouse with white trim, detached sleeves, skirt over spats, and knee boots. For ''D.C.'' and ''Cadenza'', her outfit color inverts (sky-white with blue trim), has a few places where it doesn't cover skin (compared to before), her tie becomes a two-coloured ribbon without bows (see picture), her detached sleeves are replaced with fingerless gloves and she exchanges her spats for Grade B ZettaiRyouiki.
** Manga: A printed T-shirt (the T-shirt itself is different every time), denim hip shorts, ZettaiRyouiki, and ankle boots.
* MyMasterRightOrWrong: Despite being a Fog ship, she only remembers one order, to obey Gunzou. This brings a lot of conflict to other Fog ships she ends up fighting, most of all Kongou.
* MysticalWhiteHair: She has white hair, which hints at her being a Fog ship.
* RapunzelHair: She has waist length hair.
* ReiAyanamiExpy: In the anime only.
* ScrewTheRulesImDoingWhatsRight: [[spoiler:In episode 10, after suffering from a surprise attack from I-400 and I-402, I-401 begins to break down from sinking into the ocean. Gunzou orders her to gradually cut power to parts of the ship, and eventually orders her to cut off life support functions to preserve her remaining energy. Although she usually follows his orders without question, in this instance she became very conflicted about whether to save him, or let him die and continue the mission of getting the vibration torpedoes to America. So she instead decides to jettison her core and himself in a life pod in an attempt to hold out a bit longer, and fortunately for her, Takao finds them and gives up her nanomaterials to ensure both of them survive.]]
* SelfDuplication: She has one main form and several numbered clones running around the submarine, taking care of various tasks.
* SpaceshipGirl: When you get down to it, Iona ''is'' the I-401, and most of Blue Steel is just taking up living space inside of her.
* TheStoic: Moreseo in the anime than the manga.
* SugarAndIcePersonality
* TalkingToHerself: With her other triplet sisters in the drama CD. In the anime each of the 400-series subs has their own voice actress.
* UndyingLoyalty: She's VERY loyal to Gunzou, but as a result she tends to become conflicted whenever a situation arises where his life gets put in danger. See chapter 73 of the manga, and episode 10 of Ars Nova.

!!Sou Oribe
[[caption-width-right:200:Sou, as he appears in Ars Nova.]]

->Voiced by: Creator/TomokazuSugita (Drama CD), Shinobu Matsumoto (Anime)

The First Mate of I-401, Sou generally provides inventory of their supplies as well as aiding Gunzou with tactical decisions.
* ChildhoodFriend: He and Gunzou have known each other since elementary school.
* CoolMask: He has two; the first allows him to interface directly to 401's systems, likely equipped with a HeadsUpDisplay. He has a second, smaller one to use when maintaining the first. The reason for the mask has yet to be revealed, although the presence of what looks like a respirator and oxygen supply hints it may be medical (in ''Ars Nova'' he makes the hasty excuse that it keeps his allergies in check).
* MrExposition: Particularly in the early chapters as [[AsYouKnow briefings to the other crew]] so the reader can familiarize themselves with some of the terminology and concepts used in the rest of the series.
* NumberTwo
* TheBlank
* TheFaceless: Always has his helmet on. He claims it's easier to contain his allergies this way.
* TheGraphShowsTheTrend: He loves them.
* TheUnreveal: He's opened the mask only once in flashback but we only see [[OOCIsSeriousBusiness Gunzou's reaction]].

!!Kyouhei Kashihara
[[caption-width-right:200:Kyouhei, as he appears in Ars Nova.]]

->Voiced by: Creator/MinoruShiraishi (Drama CD), Eiji Miyashita (Anime)

Weapons officer of I-401, Kyouhei is generally most active when they are fighting an enemy. Otherwise serves as comic relief and occasionally as audience surrogate.
* BigEater: Not so much in quantity as frequency: it's a common sight to see him eating some kind of snack while others are talking. He's even got a cooler installed at his workstation!
* BlackDudeDiesFirst: He's noticeably darker than the rest of the cast and [[spoiler: his decoy]] was the first killed at Iwo Jima.
* CoolShades
* TheGenericGuy: Compared to the others, at least. All of the human officers who came from the nautical school belonged to the top ten of their cohort with the sole exception of Kyouhei, whose grades were consistently mediocre. He ranked within the top 10 in weapons training though, so his position on the crew is justified.
* HiddenDepths: He might be a goofball weapons specialist but there's been hints that Kyohei is a bit of a history nut, not least of which is his tattoo that reads "man of the sea" in ''Sumeric cuneiform''.
* HotBlooded
* {{Otaku}}: A mild case, since only him and Iona watch anime aboard the ship.

!!Iori Watanuki
[[caption-width-right:200:Iori, as she appears in Ars Nova.]]

->Voiced by: Creator/AkiToyosaki (Drama CD), Minami Tsuda (Anime)

The Engineer of I-401, she does all the humanly-possible maintenance aboard the ship and keeps Iona's heavily-modified engine running smoothly.
* CuddleBug: Is sometimes seeing hugging Iona or her mini metal models.
* {{Gainaxing}}: Usually underplayed but she has some of the most motion of the cast (only behind Takao in ''Cadenza'').
* GirlishPigtails
* ScottyTime: [[spoiler:Almost]] Always ahead of every engine failure, breakdown or last-second power boost needed. Which is ''really'' handy, because it happens a lot.
* TheEngineer: Of the Mechanic variety.
* TomboyWithAGirlyStreak
* WrenchWench: Comes with being the engineer.

!!Shizuka Houzumi
[[caption-width-right:200:Shizuka, as she appears in Ars Nova.]]

->Voiced by: Creator/NaoTouyama

The sonar operator of I-401, she plays the crucial role of locating various hazards outside the sub via sonar.
* BewareTheNiceOnes: Oh hell yes. The Japanese special forces found this out the ''hard'' way.
* HimeCut: Befitting of her quiet temperament and [[SilkHidingSteel ladylike]] traits.
* {{Meganekko}}
* MysteriousPast: There's really not a lot known about Shizuka's past, but her own comments so far point that she spent part of her childhood in Taiwan, and that her father likely played a part in designing the security protocols that the Japanese ground forces still uses in the present day.
* NakedPeopleAreFunny: Once forgot to get dressed when surprised by a combat alert.
* TheQuietOne

[[caption-width-right:200:The {{Tsundere}} Heavy Cruiser.]]

->Voiced by: Creator/RinaSato (Drama CD), Creator/ManamiNumakura (Anime)

Heavy Cruiser of the Fleet of Fog, she is the first named Fog ship Blue Steel battles and defeats (though chronologically speaking that honor would go to Hyuuga) in the series. When she is surprisingly let go by Gunzou in the wake of that battle, she develops a girlish fixation on Blue Steel's commander and, by extension, Humanity in general, to the point where she literally goes AWOL from the Fog Fleet.

Takao herself is the main character of the manga spinoff '''Salty Road''', which focuses on what she's been up to at Yokosuka, along with her minders Zuikaku and I-402.
* BoobsAndButtPose: She is introduced in the Anime opening through this pose.
* BreakoutCharacter: Takao quickly became a fan favorite after her introduction, leading [[WordOfGod the authors to completely alter their plans for the character]]. She's been an ever-reliable source of comedy ever since.
** She is also the only Fog Fleet character to headline her own spin-off manga, ''Salty Road''
* CanNotSpitItOut: Attempted to make a love confession to Gunzou... and [[CrowningMomentOfFunny failed miserably]].
--> '''Takao''': A maiden's heart is complicated!
--> '''Hyuuga''': Then maybe you shouldn't have installed a maiden plugin!
* CombatPragmatist: Something she learned from Gunzou
* HeelFaceTurn: Runs away from the Fog and joins Blue Steel.
* HeroicSacrifice: Anime-only:She uses the remainder of her nanomaterials to restore Iona back into working order, though she loses her ship and her Mental Body in doing so. [[spoiler:Suberted, her core survived and she is still able to at least turn up on screens or as projections on board the ship. Her mental model is fully restored during the last episode episode credits.]]
* InSeriesNickname: Tsundere Heavy Cruiser. Sees regular use by the Yamato-aligned Fog Ships like I-402 and Zuikaku.
* InstantCosplaySurprise: Is on the receiving end of several rapid-fire costume changes courtesy of Yamato. Notable in that the switches really are instant, illustrating just how out of her league Takao is against Yamato.
* IWantMyBelovedToBeHappy: [[spoiler:In episode 10 of the anime, she sacrifices her ship and mental model after she locates the remains of I-401, and a barely alive Gunzou inside a lifepod with Iona's core inside.]]
* MacrossMissileMassacre: Takao's deck plating can lift aside to reveal as many as ''one hundred and twenty'' launch tubes. Part of her character development is learning when to hold back on the firepower.
* MidSeasonUpgrade: Care of Hyuuga in ''Cadenza'', and one that Takao did ''not'' appreciate: [[spoiler:a pair of gigantic magma boring drills.]]
* RapunzelHair: Though it is not directly visible because her ponytail is usually put up in a complex corkscrew, when loose her hair reaches her ankles.
* RedAndBlackAndEvilAllOver: She's the series StarterVillain, and her ship's sinister red-and-black colour scheme means she looks the part, but she promptly performs a HighHeelFaceTurn and turns blue.
* ShesGotLegs: More prominently displayed in some of the [[ anime artwork.]]
* StalkerWithACrush: To Gunzou.
* StarterVillain: She's the first Fog warship the I-401 has a proper on-screen battle against. [[HighHeelFaceTurn The 'villain' bit doesn't last long, though.]]
* ThemedAliases: The surnames that Takao used during her forays into human society reflect the aliegances she had at that point: '''Kirino''' (literally "of the Fog") after the first time she was defeated by Gunzo, and '''Aoki''' (can be read as "pure blue") after she had fully aligned herself with Gunzou and Iona's Blue Fleet.
* ThoseTwoGirls: With Hyuuga, after she found her way to Blue Steel's island stronghold.
* {{Tsundere}}: She's a Sweet type, which is acknowledged by most characters. She'll be gentle and nice to you, but '''do not''' make fun of her.
* SelfDuplication: Like Iona, she too has several mini models that helps her in doing mundane tasks.
* UnlimitedWardrobe: Like all mental models, she can change clothes as she wishes, but she's one of few who doesn't stick to one set.
* YouGottaHaveBlueHair: She has blue hair.

[[caption-width-right:200:Part-time port manager, full-time Iona Worshipper.]]

->Voiced by: Creator/SakiFujita (Anime)

Former flagship of the Fleet of Fog Second Oriental Fleet. Sunk by Blue Steel before the events of the series and took up a job as port operator on Iwo Jima
* CatSmile: All the time.
* CleavageWindow: Not as evident as with the usual examples, but her Mental model in the ''Ars Nova'' anime sports these.
* ExcuseMeWhileIMultitask: Her schtick in ''Ars Nova''. She can quite easily [[spoiler:fend off rockets while talking to Kongo across Iwo Jima and]] talk to Makie while fighting Takao for [[ItMakesSenseInContext food]].
* GadgeteerGenius: For one thing, she built an army of robots, after extracting the raw materials from the Earth herself, since she didn't want to use nanomaterials. She's also built a set of "Option Ships" Iona can [[CombiningMecha dock with for a major power boost]].
* GeniusBruiser: She commonly acts as TheSmartGuy for Blue Steel but make no mistake, she's all but unstoppable in a fight against anyone who's not another Mental Model.
* GenkiGirl: Acts this way towards Iona frequently.
* TheGlomp: She loves doing this to Iona.
* [[spoiler: HeroicSacrifice: Took Hiei down with her to buy time for Iona's escape. Thanks to [[SuperToughness just how resilient]] Union Cores are, they're both NotQuiteDead.]]
* HighClassGlass: Sports one with a gold frame as part of her mental model
* HotScientist: Presents herself as one with her mental model, complete with...
* LabcoatOfScienceAndMedicine: Her signature style. It doubles as a BadassLongcoat and since it's made of nanomaterial she can alter how long it is, which she does [[ purely for dramatic effect]].
* LoveAtFirstPunch: With 12 corrosive torpedoes.
** Her ([[UnreliableNarrator heavily biased]]) recollection of the battle between her and Iona is [[InterplayOfSexAndViolence heavily sexualized by herself]].
* PowerFist: Chapter 34 of the manga gives her a pair of '''huge''' ones, each bigger than her torso.
* RocketPunch: The aformentioned power fists.
* StalkerWithACrush: To Iona.
* ShipperOnDeck: [[JustForPun Ships]] Gunzou and [[spoiler:Takao]]. Mostly because she wants Gunzou away from her Iona-neesama, so she can have her to herself.
* ThoseTwoGirls: With Takao. Usually butts heads with her, but will nonetheless help her out when needed. Apart from her ShipperOnDeck status (see above.)


!The Fleet of Fog (Japan)

The segment of the Fog Fleet blockading the Japanese islands, the Mental Models of its ships are the only ones the audience has met so far. Ostensibly under the direct command of Superbattleship Yamato, the responsibility for actually maintaining the blockade falls under Flagships Nagato (First Fleet) and Kongou (Second Fleet).

[[folder:Members of the Japanese Fog Fleet]]


[[caption-width-right:200:Hail to the Queen, baby.]]
->Voiced By: Creator/MaiNakahara (Ars Nova Cadenza)

Supreme Flagship of the Fleet of Fog, and chronologically the first among the Japanese Fog Fleet to gain a Mental Model. Disappeared without a trace during the Great Naval Battle seventeen years ago, made an unexpected return to the fleet two years before the start of the story with a Mental Model. It was her decision for other Fog warships to generate Mental Models as well.

[[spoiler:As Hyuuga and Takao soon discover, Yamato's mental models look ''exactly'' like Kotono Amaha, Gunzou's childhood friend, who was believed to have died two years prior.]] This casts her keen interest on Humanity in general, and the activities of Iona and her crew in particular, in an altogether new light, especially since (in the manga anyway), it was Yamato herself that "suggested" to Iona to seek Gunzou out.
* AdaptationalCurves: Yamato is far bustier in ''Cadenza'' than she is in the manga, and shows off a good deal more cleavage.
* CainAndAbel: Despite being the older sister, she's the one who was first offed by Musashi in Cadenza. [[spoiler:Temporarily, anyway.]]
* DeathByAdaptation: In the ''Ars Nova'' continuity, as revealed in the ''Cadenza'' movie, where she was apparently destroyed by Musashi two years prior to the start of the story. However...
** NotQuiteDead: [[spoiler:She was able to transfer part of her memories and personality to Iona, to guard against the day when Musashi finally makes her move against Humanity.]]
* HumansAreSpecial: What she thinks in ''Cadenza''. [[spoiler: It's the reason why she fights against Musashi at the start of the movie, and why she eventually sends Iona off to Gunzou, so that Mankind will have a fighting chance against Musashi.]]
* LadyOfWar
* MysteriousBacker: Not that Gunzo and his crew are any wiser, but Yamato is helping them out, to the point where she assigns Yukikaze to keep an eye on Iona, discretely of course.
* OrcusOnHisThrone: Yamato has yet to do much of anything all series save for pointing people where she wants them to go. You just know that when she's ready to make her plans known, it's going to be ''big''.
* PerpetualSmiler
* SingleMindedTwins: Averted. Unlike Nagato, Yamato's two Mental Models display distinct personalities, with one still acting like prim and proper princess, and the other... [[spoiler:acting exactly like Gunzou's dead childhood friend Kotono Amaha]].
* TheChessmaster: Yamato is planning ''something''. She's not saying what that something is, but she's been encouraging select subordinates to spend time learning about humans.
* TheOjou
* {{Troll}}: In the [[BonusMaterial very non-canon extras]] included in each manga volume, Yamato takes particular pleasure in trolling her subordinates I-400 and I-402.
* WorthyOpponent: Respects humanity for their strategic skills and will to keep fighting the Fleet of Fog despite the odds.

[[caption-width-right:200:The Iron Lady of the Fog.]]

->Voiced by: Creator/HoukoKuwashima (Drama CD), Creator/{{Yukana}} (Anime)

Flagship of the Second Oriental Fleet (Third Oriental Fleet before reorganization). Serves as the primary antagonist in ''Ars Nova'' and a major antagonist in the manga.
* AdaptationPersonalityChange: Let's just say that when one version acts as the "FinalBoss" in an arc that spanned ''several books'', while the other not only arrives as THE most powerful member of TheCavalry for the heroes, but actually gives one of the main characters a speech that raises her flagging confidence, then a divergence happened ''somewhere'' along the way.
* ArtEvolution: Kongou's design has changed slightly over the course of the manga, primarily in her face which has become more mature and sharply featured. Her appearance in ''Ars Nova'' matches that of the early manga chapters.
* TheCavalry: In ''Cadenza'', where she's the last to arrive and assist Blue Steel in breaking Hiei's blockade.
* EmotionlessGirl: Manga Kongou certainly believes this, as she thinks that emotions make the Fog inefficient and distracts its members from their purpose as weapons.
** The Kongou in ''Ars Nova'' however is convinced in the end that emotions ''are'' important facets of an individual, which each Fog Ship capable of creating Mental Models are becoming, and as such can't be ignored or set aside.
* EstablishingCharacterMoment: In the prologue for Episode One of the anime, a bit of the Last Great Battle is shown. In it, Kongo is shown at the head of the line (distinguished by her purple glow), and engages the human ships via [[RammingAlwaysWorks ramming]] them, hinting at the brute force method of solving problems she will exhibit later on.
* FanservicePack: In ''Cadenza'', Kongou wears a much more revealing outfit and appears to have larger breasts compared to ''Ars Nova''.
* GracefulLadiesLikePurple / PurpleIsPowerful: Imbues elegance of a ProperLady through her mental model, while at the same time being one of the most powerful ships of the Fleet of Fog. Becomes more evident with her new dress in ''Cadenza''.
* HimeCut: Modified by her usual style of tying her hair into the distinctive 'puffball' pigtails. After activating her Flagship equipment, she lets her hair down (and [[RapunzelHair grows it out]]) for the full effect.
* ImplacableWoman: She becomes extremely obsessed with Iona and attempts to sink her at all costs.
* LickedByTheDog: In the manga, seagulls seem to like her. A lot. Spoofed in the Fog Theater shorts after every chapter.
* MidseasonUpgrade:
** In the manga. She gains access to Flagship Equipment care of Akashi, which aside from giving her a nice new gown and hat, turns her into a one-woman ZergRush: she is able to "transport" Fog Vessels from other parts of the Japanese archipelago to her location, giving them new bodies to transfer their cores to. In essence, a battleship-sized 3D printer.
** In the Anime, [[spoiler:after realizing that Maya was nothing more than a puppet controlled by [=I-400 and I-402=],]] she absorbs [[spoiler:Maya]] and converts her ship into a floating [[Franchise/StarWars Death-Star]]-like fortress with an oversized WaveMotionGun.
* MyMasterRightOrWrong: While she dislikes Yamato's idea that the Fleet of Fog should have Mental Models and humans to help them in their goals, she nevertheless obeys.
* PreAssKickingOneLiner: Gives one to Hiei in ''Cadenza'', when the former questions why she had the gall to show up ''now'', and only to support Blue Steel.
--> '''Kongou:''' ''I'' decide where I go and when I return.
* {{Pride}}: Kongou has a LOT of pride, both in herself, her capabilities, as well as the superiority of the Fog Fleet in general. Even more so in the manga, but its ''because'' of this pride that Blue Steel is able to counter her time and again, culminating in her defeat, despite the overwhelming numbers of her fleet AND having Ise with her. Iona says as such, in TheReasonYouSuckSpeech she gives once Kongou realizes that she's been played, HARD.
--> '''Iona''' (just as her Seirans unload their deadly payload of corrosive missiles on Kongou): A pride that isolates you is too superior for those of us who appeared on this earth.
--> '''Kongou''': What is so wrong about being superior?
--> '''Iona''': The name of that sort of pride... is simply '''arrogance'''.
* RammingAlwaysWorks: See EstablishingCharacterMoment. Comes full circle in ''Cadenza'', where Kongou ''plows through Hiei's Graviton Cannon blast'' in order use her ship body ([[ which had separated as if it were gigantic pliers]]) to hold Hiei in place.
** In manga, [[spoiler:she rams Matsushima with her prow in a last ditch effort to off Gunzou. After the rest her hull was reduced to sinking debris.]]
* RedEyesTakeWarning
* SexyBacklessOutfit: What she wears when she makes her triumphant return as part of TheCavalry in ''Cadenza''.
* TheStrategist
* TheStoic
* ShesGotLegs: The art rarely misses an opportunity to show them off.
* TakingYouWithMe: When she's finally defeated in chapter 72, Kongou makes a point of destroying the ''Matsushima'' before her reactor explodes, [[spoiler: possibly killing Gunzou]].
* TheReasonYouSuckSpeech: Both the giver of, AND the receiving part to, in Ars Nova and the manga.
** In the manga, Iona gives her one upon Kongou's defeat, explaining that Kongou's self-confidence and sense of superiority is just arrogance, a weakness rather than a strength.
** In the ''Cadenza'' movie, she gives this to Hiei:
--> '''Kongou:''' Hiei, let me enlighten you: you use rules for self-discipline. You ''don't'' force them on other people.
* TookALevelInBadass: In her early appearances Kongou seemed almost lazy, content to keep the status quo and watch the seabirds. After losing at least five ships [[note]] Nagara, I-501, Takao (AWOL), Haruna, Kirishima, Maya is arguably a sixth since she's on extended loan[[/note]] to Iona and crew, Kongou has finally had enough and is going ''all out''. Cue her MidSeasonUpgrade and the summoning of her entire fleet with the express purpose of sinking Iona.
* TragicKeepsake: In ''Cadenza'', it's revealed that she still keeps [[spoiler:[[ Maya's piano]]]].
* VillainousBreakdown: [[spoiler:In Ars Nova, she gradually starts to act in ways that causes I-400 and I-402 to question her loyalty. Then in episode 10 of the anime, her ship is locked down by the two subs, and she also finds out that Maya, her last friend/ally, was an AI construct designed to spy on her.]]
* YouAreBetterThanYouThinkYouAre: In ''Cadenza'', it's ''Kongou'' who gives Iona a peptalk, when the latter starts doubting herself.
--> '''Kongou:''' Your existence will always stay in my heart. No matter what you become, ''I'' will remember you, and that's the proof you existed. My changed world... You're the one who brought me there.

[[caption-width-right:200:She's friendlier than she looks.]]
-> Voiced By: Creator/HibikuYamamura

Battleship of the Fleet of Fog and subordinate to Kongou. Loses her ship body when assaulting Yokosuka, leading to her fateful encounter with Makie Osakabe.
* BadassLongcoat: A rather intimidating AllEncompassingMantle variant. Its badassery is acknowledged in-universe as well - wearing it gives Haruna a significant confidence-boost. [[note]] Supplemental material in the manga reveals that losing the coat actually reduces her processing power by 100%. Losing it drastically reduces her capabilities. That said, the page in question was written ''very'' tongue-in-cheek and revealed a series of secret pockets on the inside filled with mostly useless items like snacks.[[/note]]
* CoatCape: It covers her entire body, and most of the time only the upper part of her head is visible.
* ChickMagnet: She attracts Makie and Maya very naturally.
* CryCute: When her coat is taken away, and when consoling with Makie.
* DefrostingIceQueen: She's gone from borderline EmotionlessGirl to simply TheQuietOne. Time will tell if she softens to anyone but Makie or Kirishima, but now that she's joined the naval academy (undercover) [[spoiler:she's not even wearing her coat!]]
* GirlishPigtails
* HeelFaceTurn: Saving Makie definitely counts, though she does not want to join Blue Steel.
* HiddenHeartOfGold: She might seem stoic, though she does not hesitate when Kirishima or Makie is in danger.
* InstantCosplaySurprise: By Makie.
* MamaBear: Woe betide those who would harm Makie. Her destruction of an entire army division with armored support was ''holding back''.
* OneManArmy: She goes VideoGame/DynastyWarriors style on invading human soldiers and vehicles when Makie is threatened.
* RedOniBlueOni: Blue to Kirishima's red.
* SleepCute
* SureLetsGoWithThat: Makie discovers Youtaro [[ItMakesSenseInContext (actually Kirishima)]] is now mobile:
--> '''Makie:''' Are you involved in top-secret government projects and stuff?! [[ChildProdigy Like me?!!]]
--> '''Haruna:''' Er... I... Uh, yes..?
* TheStoic: Most of the time, especially when her mouth is covered by the collar of her coat.
** NotSoStoic: Without her coat, or if her mouth is visible. Not even the coat could hide her emotion when [[spoiler: Doctor Osakabe died.]]
* ThemedAliases: She takes the Osakabe surname [[spoiler:when she infiltrates Yokosuka as a student]]. Despite how Kamikage comments on how, much like Takao before her, Haruna's alias isn't very creative, the fact that she even used that surname is meaningful on MANY levels.
* TookALevelInBadAss: After losing her ship body.
* VillainousBreakdown: [[spoiler:Professor Osakabe's death]] sends Haruna's emotions into a destructive feedback loop. She very nearly launches an annihilation attack on all three Japanese capitals before [[DeusExMachina the Admiralty Code steps in]].

[[caption-width-right:200:Once upon a time, she wasn't ALWAYS a bear...]]
-> Voiced By: Creator/YumiUchiyama.

Battleship of the Fleet of Fog, subordinate to Kongou. Lost both her ship body and Mental Model at Yokosuka and has been forced to run around as a stuffed bear ever since.
* BadassLongcoat: In the manga.
* BareYourMidriff: Her original, pre-sinking outfit in the manga was a BadassLongcoat and matching business suit which only buttoned from the collar to her sternum, leaving her midriff in full view. Her outfit in the anime (pictured), despite being more revealing elsewhere, only had a thin strip of skin showing between her trousers and shirt top.
* ButtMonkey: Poor Kirishima often gets the short end of jokes as Yotarou the stuffed bear.
* ExpressiveMask: Often, as Yotarou.
* FashionableAsymmetry: In the anime, though the design was first revealed on the cover of Book 4.
* {{Irony}}: Prior to her battle with the I-401 (and the ''Hakugei'' in the manga), she sneers at the idea of regret and humans expressing it. Guess what happens after her defeat at their hands...
* JerkAss: Before losing her ship.
* JerkWithAHeartOfGold: The HumiliationConga of getting sunk and getting reconstituted as a stuffed bear has mellowed her out. She's been ready to be the fall-guy when trying to explain things with Kongo and puts considerable stock in loyalty.
* LargeHam
* NoKillLikeOverkill: Used to love this trope. The [[CombiningMecha combination play]] with Haruna (that ultimately got them both sunk) was intended to utterly wipe Iona and crew from existence, just to make sure they ''stayed'' dead.
* PintsizedPowerhouse: After being reconstructed with part of Haruna's nanomachines and gaining control of one of Makie's stuffed dolls. Even in this form she can still knock out soldiers with ease. [[spoiler:In the manga, the stuffed doll is actually a costume the now chibified Kirishima wears.]]
* {{Pride}}: A traits of hers and what led to her downfall. Haruna and Kirishima could have defeated both the I-401 and Hakugei had they call the rest of the 2nd Oriental Fleet for backup but refuses out of her desire to claim credit in defeating the I-401.

[[caption-width-right:200:ITS A CARNIVAL, 24-7!]]
-> Voiced By: MAKO.

Heavy Cruiser of the Fleet of Fog, currently under Haruna's command and calls her "The Flagship of My Heart". Collects musical instruments and plays all of them (it took her a while to recreate a piano correctly).
* BrokenRecord: She once spammed Kongou's comms channel by singing a song ''189567 times'' before being interrupted by Haruna. Even assuming the song was only a second long, that's still ''[[MadnessMantra fifty-two hours non-stop]]''. She could of course just have been exaggerating.
* ButtMonkey: She gets easily hacked by the other Mental Models.
* DeathByAdaptation: In the ''Ars Nova'' anime. Her ship body is even absorbed into Kongou during the finale.
* GenkiGirl: Most of the time. [[spoiler:In Ars Nova, after the revelation that she's an AI construct designed to spy on Kongou, this attitude takes on a creepy undertone when she starts to repeat herself to Kongou.]]
* MadnessMantra: Her oft-quoted line "It's a carnival!" is used ''once'' in the manga. In ''Ars Nova'' she's stuck saying it in a loop after [[spoiler:her mind is wiped by the I-400 twins and left to guard/annoy Kongou.]]
* MoreDakka: It's clear that the Fog like this trope, but she likes to take it to a ''[[UpToEleven to a completely different level]]''.
-->It's a CARNIVAL! ''(shoots '''everything''')''
* PerkyFemaleMinion: Her current occupation under Haruna which she's found very enjoyable.
* PluckyComicRelief: Despite being Haruna and Kirishima's bodyguard in the manga, her role has been to give more levity to the otherwise serious nature of their visit to Hokkaido.
* SelfDuplication: Uses her mini models as an orchestra.

[[caption-width-right:200:The will be ORDER, even if she has to kill everyone else to get it.]]
-> Voiced By: M・A・O.

Battleship of the Fleet of Fog and subordinate to Kongou, leader of the self-governing body "Student Council" formed with the Myoukou-class cruisers.
* CompositeCharacter: Her incarnation in ''DC'' and ''Cadenza'' takes aspects from other manga ships and Mental Models, such as the Mirror Ring system of the U-2501, and Manga!Kongou's assertion that the Fog Fleet needs to return to the emotionless state they had prior to gaining mental models. She even quotes Kongou (in her Flagship Equipment form) word-for-word.
* TheDragon: To Kongou. [[spoiler: To Musashi in the movies.]]
* OhCrap: In ''Cadenza'', she does ''not'' take Kongou's arrival as one of Blue Steel's reinforcements well.
* OrderVersusChaos: She believes the Fleet should be orderly and not chaotic which is why she hates Hyuga.
* TheRival: To Hyuuga. Hiei doesn't like the former 2nd Fleet Flagship because her eccentric behavior rubbed off on Takao, Haruna, Kirishima and Maya, her subordinates at the time, which lead them to have their own personalities and to defect from the Fog.
* {{Roboteching}}: Hiei's "Sniper System" lets her bend the beam of her WaveMotionGun significantly off-axis. The system is apparently unique to her.
* ShutUpKirk: In ''DC'', she verbally stonewalls Iona's attempts at trying to find a non-violent resolution with her.
* StudentCouncilPresident: She and her own [[QuirkyMinibossSquad personal squadron]] wear matching Student council uniforms.
* ZettaiRyouiki: A solid Type A.

[[caption-width-right:200:The Vice President.]]
-> Voiced By: Aya Fukuhara.

Heavy Cruiser and Hiei's second-in-command of the "Student Council". Takes considerable pride in her abilities and role as Vice-President of the council (although she's still not sold on the uniform).
* {{BFG}}: Her Super-Gravity Cannon takes the form of a ''pair'' of colossal gun barrels longer than her own hull.
* ColdSniper: Calm, collected, and specialized in delivering one-hit-kill shots.
* EyepatchOfPower: Linked to her main cannons as a targeting display, it's otherwise decorative and removable.
* FashionableAsymmetry: Her knee-socks are of different lengths. She and Haguro both wear a single armoured bracer in the manner of Japanese archers [[note]] Myoukou's is on her left arm, Haguro's is on her right.[[/note]] The hemlines of all "Student Council" jackets (save Hiei herself) are longer on the left side.
* TheDragon: To Hiei.
* [[YouGottaHaveBlueHair You Gotta Have Light Purple Hair]]

[[caption-width-right:200:The Devil's Ears.]]
-> Voiced By: Satomi Satou.

Sister ship of Myoukou, has top-notch sonar and communications gear and serves as the ears of Hiei's "Student Council".
* NecessaryDrawback: She has the best sensor suite of Hiei's escort fleet, but in return she had to get rid of her Graviton Cannon to fit all of it in her superstructure.
* RecursiveAmmo: Nachi's signature attack is to launch one or more ICBM-sized missiles at the target, each of which is carrying between 12 and 16 torpedoes.
* RedOniBlueOni: The Blue to Ashigara's Red.
* TheQuietOne: Has a very muted personality compared with her sisters.
* TheSmartGuy: Is ''constantly'' asking Ashigara to slow down and ''study the data'' before charging into combat.
* [[YouGottaHaveBlueHair You Gotta Have Lime Green Hair]]

[[caption-width-right:200:The Little Sister.]]
-> Voiced By: Hiromi Igarashi.

Sister ship of Myoukou and member of Hiei's "Student Council". Initially an escort of Hiei and Myoukou, has since teamed up with Ashigara after they were both sunk by Iona.
* AdaptationalBadass: In the manga, Haguro was the first victim of Iona's strategy against Kongou, and her ship body went down without even firing a shot, on top of her Union Core ending up in a sharks belly. In ''Cadenza'' though? She manages to disrupt Takao ''and'' Haruna due to her speed.
* {{Expy}}: To KantaiCollection's Shimakaze, of all people, in the ''Ars Nova Cadenza'' movie.
* HeelFaceTurn: For the time being, as Iona's "guests" she's stuck helping with the extra bridge duties alongside Ashigara.
* HumiliationConga: Forced to wear Hiei's "Student Council" uniform, was the first one sunk by Iona, reduced to only her (totally helpless) core and then ''swallowed by a shark''. Now that she's been rescued she's still stuck playing second fiddle to Ashigara.
* NecessaryDrawback: She's the fastest of Hiei's escorts in the ''Ars Nova'' movie, but like her sisters she had to get rid of her Graviton Cannon to get her speed.
* TokenMiniMoe: Is notably younger looking than the other members of Hiei's group, appearing only as a pre-teen instead of the more typical mid-late teens of the other members.

[[caption-width-right:200:The Hungry Wolf.]]
-> Voiced By: Creator/SuzukoMimori.

Sister ship of Myoukou and final member of Hiei's "Student Council". Initially paired with Nachi, has wound up with Haguro after they were both sunk by Iona.
* ActuallyPrettyFunny: After getting beaned in the face with a torpedo, Ashigara floats stunned to the surface before cracking up with laughter.
* AdaptationalBadass: Much like Haguro, Ashigara makes a FAR better showing in ''Cadenza'' than in the manga, up the point where she gives Takao a run for her money.
* BloodKnight: As happy and energetic as she is, what she wants in the end is to fight. Her attitude to it is reasonably honourable, since she wants a fair fight, and won't sink an enemy outside battle.
* BoisterousBruiser: She ''really'' likes to get straight into combat. The moment Iona was detected she dove headlong into the water, knowing full well that it meant she could only use torpedoes (which she's not very good with). The ''Ars Nova Cadenza'' movie [[CharacterExaggeration exaggerates]] her personality to full GenkiGirl levels of hyperactivity.
* ButtMonkey: Often self-inflicted, Ashigara's tendency for bull-rushing into a fight means that she doesn't get much respect ''and'' makes her defeats the most humiliating.
* CuteLittleFangs: Highlighting her [[BloodKnight aggressive nature]], she sports a pair of fangs.
* GenkiGirl: In ''Cadenza'', she's barely ever still, and is constantly spinning, moving, or otherwise bouncing around. Most of the time, she's expressing her will and want to fight.
* HeelFaceTurn: Time will tell if it will stick, but for now both she and Haguro are assisting with the bridge duties onboard Iona.
* HairDecorations: She wears a pair of stylised wolf hair clips above her ears. Along with her CuteLittleFangs it's referencing her RealLife counterpart's nickname "The Hungry Wolf".
* HimeCut: With bonus OjouRinglets at the ends of her long side locks. Amusingly, common tropes associated with this hairstyle ''don't'' apply to Ashigara.
* OOCIsSeriousBusiness: Ashigara drops the genki girl act entirely when Iona decides to try and recover the Matsushima in the wake of the MutualKill between it and Kongou, as she sees it as needlessly reckless ''especially'' since there's still a hostile fleet on the surface, and the fact that I-401 is barely in fighting condition after the fight with Kongou.
* RedOniBlueOni: The Red to Nachi's Blue.
* TakingTheBullet: In the manga, she blocks a full spread of Iona's corrosive torpedos aimed at Kongou, and her ship body gets sunk as a result.
* WorthyOpponent:
** ''Wants'' to be this for Iona, believing in the Fair Fight. [[spoiler:This is why she refuses to simply scuttle Iona from inside when she and Haguro end up in Iona's engine room.]]
** Becomes this for Takao in ''Cadenza'', ''especially'' when Hyuuga reveals the "additions" that she made to Takao's superstructure.

Battleship of the Fleet of Fog, and Hyuuga's twin sister. She had a pretty minor role, until her Union Core is summoned by Kongou via her Flagship Equipment to aid the latter in sinking Iona. Since Kongou's defeat she is now ''de facto'' leader of the second patrol fleet.
* AllForNothing: Ise is developing a personal grudge against Iona for "kidnapping" her sister, Hyuuga. Little does she know that Hyuuga switched sides willingly, and isn't even on the I-401.
* TheDragon: For Kongou, after Hiei gets taken out by Hyuuga.
* TheDreaded: Hyuuga is ''terrified'' of her sister. Given her [[MyBelovedSmother obsessive/possessive behaviour]], this is probably well-founded.
* TheGhost: Was only vaguely referred to prior to her introduction in Chapter 63.

[[caption-width-right:200:Always one step behind.]]
->Voiced by: Creator/AoiYuuki

Fleet of Fog submarine, member of Yamato's Intelligence Fleet and is loyal to the flagship before all else. Looks exactly like Iona, save for her costume.

While in the manga, I-400 and I-402 are the left and right hands of Yamato, in Ars Nova they are shown to be agents of the Admiralty Code and, by extension, [[spoiler:Musashi, who in ''Ars Nova Cadenza'' was revealed to have usurped the Admiralty Code through sinking her sister ship Yamato.]]
* AdaptationalVillainy: In the Ars Nova anime, where it's revealed that she and her sister I-402 have been playing Kongou like a fiddle the whole time.
* DeathByAdaptation: Is sunk by Iona in the ''Ars Nova'' anime.
* IHaveTheHighGround: I-400 prefers observing Haruna and company from rooftops and other elevated vantage points.
* {{Qipao}}: Wears a shirt styled after one.
* TheStoic: Probably the most deadpan of Iona's two sisters, likely due to her much lower exposure to Humanity (as unlike 402, she's been tasked by Yamato to shadow Haruna's movements instead).

[[caption-width-right:200:Mom and Manager, rolled into one.]]
->Voiced by: Creator/AoiYuuki

Fleet of Fog submarine, member of the Intelligence Fleet. Also looks exactly like Iona, save for her costume.

In the manga, she is the one that retrieves Takao in the wake of her battle against Zordan, and brings her to Yamato for a little heart-to-heart. Later on, she accompanies Takao and Zuikaku to Yokosuka, where she more or less settles into the role of Takao's nanny.
* AdaptationalVillainy: See I-400's entry.
* DeathByAdaptation: See I-400's entry.
* HeelFaceDoorSlam: In the anime at least, she only start to show a tiny bit of emotion just before she got hit for shielding her sister.
* LittleMissSnarker: In an interesting bit of parallel evolution to Iona, 402 is developing a snarky personality the longer she stays in Yokosuka with Zuikaku and Takao.
* {{NEET}}: Worries she might be becoming one in the (non-canon) bonus comic strips.
* TeamMom: Settles into this role for the infiltration team at Yokosuka, where she does the groceries, cooks, and cleans the tiny apartment she shares with Takao and Zuikaku.
* {{Troll}}: Enjoys teasing Takao over her crush on Gunzo.


Flagship of the First Oriental Fleet.
* TheChessmaster: Many events in the manga wouldn't have been possible without Nagato loaning ships from her fleet, asking the right questions, or egging Kongou into action. She's shown a particular fondness for supporting Kongou's wayward subordinates, apparently [[ForTheLulz just to see what will happen next]].
* FinishingEachOthersSentences: Her two mental models do this.
* SingleMindedTwins: She has a pair of mental models as her avatar, one a shrine maiden, the other a geisha. There's very little different between them other than clothing.
* YamatoNadeshiko: There seems to be a pattern to these battleships...


A Fog "assault ship" under Nagato, she joins I-402 in infiltrating Yokosuka, and in the process becomes Takao's virtual roommate in their hideout at the docks. Contrary to most Fleet of Fog Mental Models, Zuikaku shows none of the awkwardness in interacting with the local human population, and has become sort of a regular at the local market due to the seafood she catches.
* BigOlEyebrows: Considerably thicker than average for Mental Models, when you can see them behind her bangs, of course.
* EverythingsSquishierWithCephalopods: She has a pet octopus in ''Salty Road''.
* FriendInTheBlackMarket: Zuikaku herself is this to any restaurant owners looking for fish that can't be caught close to shore, like tuna. Just don't ask how she got them. [[spoiler:Rod and reel, usually.]]
* KindHeartedCatLover: Is shown to have a cat as a pet, though fandom is divided at whether or not it's a real cat, or another mental model.
* NonIndicativeName: Zuikaku has been [[InsistentTerminology repeatedly called]] (in official materials no less!) an "assault/area suppression ship", but its obvious to all who can see that her ship body is an aircraft carrier.
* ThePiratesWhoDontDoAnything: Like all the other aircraft carriers in the Fleet of Fog, Zuikaku lost her aircraft in combat and was restricted from making any more. She took up fishing to stave off the resulting boredom.

!The Scarlet Fleet

A splinter faction of the Fog Fleet maintaining the European blockade, and commanded by Gunzou's father Shouzou, the Scarlet Fleet has notably deviated from the duties tasked to it by the Admirality Code, to the point where it's been drawn into conflict with the ''rest'' of the European Fleet (under the HMS Hood). With the Superbattleship Musashi as its flagship, the fleet seems to be tacitly supporting Shouzou's machinations toward an as-of-yet unknown goal.

[[folder:Members of the Scarlet Fleet]]

!!Shouzou Chihaya
[[caption-width-right:200:Rejoice, my son.]]
-> Voiced By: Creator/JojiNakata.

Captain of the Musashi, Former Captain of the I-401 before he defected to the Fleet of Fog. He has since then taken over most of the ships comprising the European Blockade for his own purposes, much to the alarm of the Fog Fleet stationed in those waters.
* CoolShades: Wears a black pair upon reappearing as Admiral of the Scarlet Fleet.
* FaceHeelTurn: Was a former war hero who captured the I-401. Now he's one of the Fleet of Fog commanders.
* DeathByAdaptation: While very much alive and even a major antagonist in the manga, Shouzou is revealed to be dead in ''Ars Nova Cadenza''. The Shouzou we see on-screen is a nanomaterial clone with no will of its own.
* ReasonableAuthorityFigure: He's the only human officer who was willing to negotiate with the Fog Fleet in the ''Ars Nova'' continuity, and got branded a traitor because of it. [[spoiler:In truth, his subordinates, who ''didn't'' like to negotiate, killed him during a mutiny.]]
* UtopiaJustifiesTheMeans: Based on comments made by Zordan Stark, Shouzou's aim is to use the Scarlet Fleet in unifying humanity and end the international conflicts that have plagued human history. The rest of humanity won't get a choice in the matter.

[[caption-width-right:200:This ice princess can't let it go.]]
->Voiced by: Creator/RieKugimiya

Superbattleship of the Fleet of Fog, and sister ship of Yamato. For unknown reasons, she has aligned herself with Shouzou Chihaya, and seems to be complicit with whatever plans the human captain has for the European Blockade.

She becomes the primary antagonist for the ''Ars Nova Cadenza'' movie, where she gives Humanity an ultimatum: somehow find a way to stop her at the Arctic Ocean in two days, or else she turns all the weapons of the Fog Fleet on all of Earth's populated cities.
* AdaptationalVillainy: While ostensibly an antagonist in the manga, what her being in cahoots with Gunzou's father, Musashi herself hasn't actually done anything overtly harmful to people. Compare this to her appearance in ''Cadenza'', where she's very much the BigBad AND has it in for Humanity as a whole.
* BigBad: For the ''Cadenza'' movie.
* CainAndAbel: Inverted. As the younger sibling, it's Musashi who sends Yamato into the depths of the Bering Sea.
* EntertaininglyWrong: She's utterly convinced throughout ''Cadenza'' that Yamato's been pulling the strings behind Blue Steel's actions, and using "Iona" as a mask. [[spoiler:Unfortunately when Iona reveals that she's her own person, and Yamato ''hasn't'' been actively guiding her, Musashi well and truly loses it.]]
* EyesAlwaysShut: Through the manga and most of ''Cadenza''. When she ''does'' open her eyes in the movie, it's usually for something important.
* HumansAreBastards: Her motivating factor throughout ''Cadenza'': that Humanity as a whole could not be trusted, and would be better off wiped out. [[spoiler:This was brought about by her witnessing how Shouzo Chihaya, the most reasonable human she's ever met, was assassinated by his own crew, for the simple fact that he treated her and Yamato as ''people'' rather than just evil weapons.]]
* HoistByTheirOwnPetard: Her own Mirror Ring system is used in the finale of ''Cadenza'' to defeat her once and for all, [[spoiler:when Iona-as-Yamato uses it to warp ''above'' Musashi, where the latter is essentially defenseless]].
* {{Irony}}: In ''Cadenza'' she overpowers Yamato's shields by ramming her sister-ship and then firing her Graviton Cannon point blank at her superstructure. [[spoiler:This is ''exactly'' how she is finished off in the end.]]
* InsistentTerminology: She keeps on calling Iona "Yamato's Doll" in ''Cadenza''. [[spoiler:Because she's convinced that Yamato's personality is secretly hiding underneath Iona's facade. Except she's very VERY wrong.]]
* NiceHat: In the manga she owns an astrakhan, while in ''Cadenza'' she wears a black mohair beret with a black rose pinned to one side.
* PrettyInMink: We are first introduced to Musashi in the manga wearing an astrakhan hat and a fur-lined mantle.
* VillainousBreakdown: In ''Cadenza'', Musashi essentially breaks down in a massive temper tantrum when she learns through Iona [[spoiler:who is speaking with Yamato's memories]] that, despite everything she's done, Yamato still loves her as her dearest sister.
* WhoWearsShortShorts: Her outfit for ''Cadenza'', combined with the obligatory ZettaiRyouiki.

Fleet of Fog submarine European Fleet under the command of Zordan Stark and his human crew. [[spoiler: According to battleship New Jersey, U-2501 is based around the core of ''destroyer Z1 Leberecht Maass'' and shouldn't be capable of operating half the systems she has done.]]
* CryCute: When Zordan orders her to cancel her mental model.
* DoesNotLikeShoes: Dances barefoot on her deck while she has the ability to do so.
* NoSell: The Mirror-Ring System, which is supposed to be exclusive to ''Yamato'' and ''Musashi'', lets U-2501 deflect super-heavy cannon shots.
* TokenMiniMoe: Her mental model takes the form of an adorable child, a marked contrast to her crew who are all in their mid/late teens.
* UndyingLoyalty: U-2501 is completely dedicated to Zordan, whom she considers infallible, despite the open disdain he has shown towards her.

!!Zordan Stark
Captain of U-2501. Personally trained by Adm. Chihaya, Zordan and crew have been dispatched to the Pacific to make an example of Gunzou and Iona.
* CombatPragmatist
* GermanicEfficiency: Does not like mental models because of their calculation usage. At one point, he even orders his own submarine to cancel her mental model because of it.
* EvilCounterpart: Zordan Stark serves as one to Gunzou Chihaya. Both are human captains of crewed Fog submarines, match each other in tactical skill and share close personal connections with their crews. What sets them apart is Zordan's ruthlessness and their completely opposed views on Mental Models: Chihaya considers Mental Models as people and even leaves Iona in charge of his crew when he's not there; Zordan considers Mental Models a waste of resources on a crewed ship and forbids U-2501 from manifesting one, which is a shame because the one time she did U-2501 was ''adorable''.
* SmugSnake
* TheOnlyOneAllowedToDefeatYou: Zordan and U-2501 was sent by Chihaya Shouzou himself to be Gunzou's nemesis. When ''Lexington'' and a detachment of North American Fleet ships arrive to help ''Kongou'' against Blue Steel, Zordan intercepts them and challenges ''Lexington'' to a duel, citing this trope as his justification.
* WeCanRuleTogether: After cornering the 401 and its crew, Zordan suggests Chihaya to join the Fleet of Fog under his boss, Chihaya's father.
* WolfpackBoss: Appropriately, Zordan's strategy. Alongside the ''U-2501'', he also commands a force of automated midget subs known as the ''[[GratuitousGerman Seehund]]'' (Seals), which he uses as forward attack ships. Alongside, he can sacrifice several of these subs to create functional replicas of the ''U-2501'', complete with torpedoes and other special features.

!Miscellaneous Fleet of Fog Characters

Various members of the Fleet of Fog belonging to other fleets or otherwise not directly associated with the above groups.

[[folder:Unaligned Fog Fleet Ships]]

The first Fog battleship sighted by humans. Last witness of the Admiralty Code, Flagship of the Fog's European Fleet. [[spoiler: Currently allied with Chihaya Shouzou's Scarlet Fleet to find the Admiralty Code but if the alliance will last is doubtful.]]
* GirlishPigtails
* SingleMindedTwins

A Fog battlecruiser currently on the run due to a disagreement with her former flagship, ''Hood''; while the latter advocated a direct intervention against Shouzo's Scarlet Fleet, Repulse considered the abandonment of standing orders from the Admiralty Code treasonous. When her fellow ship ''Prince of Wales'' decided to force the issue, Repulse escaped into Pacific waters instead with her escort ''Vampire'' in tow. After the intervention of the Japanese submarine ''Hakugei'' in her escape, Repulse is weighing the difficult decision of potentially cooperating with humanity.
* BoobsOfSteel: As a battlecruiser she has serious offensive firepower and is possibly the most well-endowed of any Mental Model seen so far, but somewhat subverts the trope in having [[GlassCannon weaker armor than a true battleship]] and an even weaker [[ShrinkingViolet sense of confidence]].
* PrehensileHair: A variation: it's not her actual hair, but Repulse has a pair of long ribbons on her hat which function the same way.
* {{Meganekko}}
* {{Meido}}: Not only has the uniform, but quite literally sweeps up damage with nanomaterial brooms.
* LuminescentBlush: Easily flustered and embarrassed, especially whenever Vampire brings up the potential of working with humans.
* ScrewThisImOuttaHere: Had to abandon her patrol route after Prince of Wales decided she was disobeying orders.

Repulse's escort destroyer, and the first Fog ship shown to have a personality ''before'' she was finally given a Mental Model (care of Repulse's [[RepeatingSoTheAudienceCanHear annoyed replies]]). While she obviously doesn't have high opinions of her command ship's leadership capabilities, she's decided to stick with the hapless battlecruiser in her exile to the Pacific.
* CuteLittleFangs: As befits her namesake theme. Appropriately for a vampire, [[ShownTheirWork the fangs are her second incisors and not her canines]].
* {{Meido}}: Much like her command ship, Vampire's Mental Model is themed as a Victorian Maid, though she wears a much shorter skirt, as well as a bat-themed ribbon.
* ServileSnarker: Vampire takes every opportunity to belittle Repulse's competency, but it's obvious that she's loyal to cruiser all the same.

Flagship of a detachment from the North American fleet, come to "aid" Kongou in Blue Steel's destruction.
* BadassBookworm: She's converted her hanger deck into a ''massive'' library which she's constantly leafing through. She also has a collection of antique globes and historical navigation equipment.
* NotAMorningPerson
* PhenotypeStereotype: Blond, light-colored (probably blue) eyes, ''freckles''. Definitely from the American fleet.
* ShoutOut: Lexington's sub units, rather than looking like [[FunSize miniature]] versions of herself (as seen with Iona and Takao), look like [[Film/ForbiddenPlanet Robbie the Robot]].


! Supporting Human Characters

[[folder: Japanese Government and Military Personnel]]
Current Prime Minister of the Central District of the three districts that the Fog's blockade has carved Japan into. He's proven far more adept at politics than his former naval career.

* NumberOne: Was formerly Kita's XO when they took part in the Great Naval Battle.
* FriendlyEnemy: Views Kita as this; while they're bitter political opponents, he still has affection for his former captain.
* GeniusCripple: By all accounts is a masterful political figure, despite being confined to a wheelchair with a life-support system since he was nearly killed in the Great Naval Battle against the Fog.
* GoodIsNotSoft: See the Chains of Commanding, below.
* MachineMonotone: ''Possibly''. He's yet to be voiced by an actor, but his [[PaintingTheMedium speech bubbles]] are shaped like those used for radio communications, so his voice is certainly artificial.
* {{Realpolitik}}
* ReasonableAuthorityFigure
* TheChainsOfCommanding: Is really feeling it after becoming Prime Minister. Has expressed a few times how he hates himself for having to make hard-hearted choices but holds out hope they're for the best.

!!Ryoukan Kita
Diet member and likely the next Prime Minister of the Central District.

* TheCaptain: Was formerly a JMSDF destroyer skipper, and acquainted with Gunzou's father.
* FriendlyEnemy: Views Mitsumine as this; while they're bitter political opponents, he still has affection for his former XO. That said, he's not as nice about it as Mitsumine is.
* HonorBeforeReason: Inverted, Kita gives a couple of his old Army colleges a severe dressing-down over the Osakabe fiasco, which had been motivated by the Army's overwhelming desire to do ''something'' after being sat idle since before the Great Naval Battle. After the Iwo Jima disaster, Kita resigns from office in order to minimize the fallout from the affair rather than weaken the army's position further.
* NoMrBondIExpectYouToDine: Gunzou and his crew are treated to this in episode 3/Chapter 8. During dinner [[FunnyBackgroundEvent (of which only Iori actually eats anything)]] Kita tries to convince Gunzou to return Iona to the Japanese government so they can put a "proper crew" on board. The arrival of Haruna and Kirishima adds some urgency to the discussion, but [[CasualDangerDialogue not the (strained) civility)]].
* {{Realpolitik}}: Prime Minister Mitsumine and Asst. Secretary Kamikage are his primary opponents in the power struggle within the Japanese government [[spoiler:until Kita resigns to save face for the Army]].

!!Kamikage Ryujirou
Assistant Secretary to Military Command of Ministry of Defense (later promoted to full Secretary), Kamikage is the government official most sympathetic to Blue Steel. It was his idea to use I-401 to transport the Vibration Warhead data to the USA in the first place, which forms the major plot of the franchise.

* GoodIsNotNice: Is entirely willing to play hardball with political opponents or Japanese citizens if he believes it is in the best interests of the nation. He is [[MagnificentBastard ''considerably'']] more ruthless in the anime.
* Realpolitik: The power struggle between the various parties and regional capitals in the Japanese government is very real. Kamikage, despite his relatively young age, is a consummate player.
* ReasonableAuthorityFigure: Is the highest ranking official in the Japanese government to view Gunzou and Blue Steel as assets and not liabilities. Is starting to win the Prime Minister over to his way of thinking.
* TheChessmaster: Has a lot of assets to move around the board, these only grow after his promotion. All for Japan.
* TheStrategist: As part of his job in the Ministry of Defense.

!!Cruz Herder
One of the United States Marines stationed in Japan before the fog blockade now part of the Japanese Navy as a special forces detachment.
* BadassNormal: He's yet to engage in combat but interactions with other characters detail his professional reputation as one.
* DeadpanSnarker: His casual and often irreverent mannerisms contrast sharply with the much more uptight Kamikage, his primary contact and ally in the Ministry of Defense.
* OlderThanHeLooks: Given his training and the amount of time confined to Japan, Cruz is probably in his forties. Not that you'd know by looking at him.

!!Daisaku Komaki
Captain of the Hakugei 3, Japan's latest and greatest submarine.
* {{Adorkable}}: Badass ship captain, yes. Completely useless when it comes to women, oh yes. His bumbling attraction to Mauri makes him one of the most endearing of the human characters.
* BadassNormal: Becomes captain of the first man-made ship to sink a Fog warship. That it was Haruna and Kirishima ''at the same time'' just makes the victory all the sweeter. [[spoiler:Willing to intervene in the escape of ''Repulse'' and ''Vampire'' into the Pacific.]]
* HotbloodedSideburns: An understated, well-trimmed example, but they do go all the way to his jawline.

!!Maruri Hibiki
->Voiced by: Creator/KanaHanazawa

Former Sonar operator of I-401. Transfers to the ''Hakugei'' because of her experience in Blue Steel.

* AllLoveIsUnrequited: Is still holding a candle for Gunzou. His inability to notice her affection and the ''massive'' guilt he carries from losing Kotono is a big part of why she left Blue Steel and rejoined the Navy.
* LoveCannotOvercome: Even though she was the first crew member to join the Blue Steel because she was in love with Gunzou, she couldn't handle the risks of being in Blue Steel.

!!Makoto "Osakabe"
Prime Minister of the Northern District and a Design Child.
* ArtificialHuman
* CreepyChild
* DudeLooksLikeALady
* TeamSwitzerland: Is willing to support either the Japanese government or the Fleet of Fog as long as Hokkaido benefits from the alliance.
* TheLeader: Was genetically engineered to be a capable leader without humans flaws like corruption or greed.
* TheStoic: Neither is he capable of strong emotions, being engineered to be objective and dispassionate. His concern for Makie and by extension [[spoiler:Haruna, Kirishima and Maya]] is noted by himself as deeply uncharacteristic.


!!Makie Osakabe
[[caption-width-right:200:The Young Genius.]]
-> Voiced By: Sayuri Hara.

A young girl living a secluded life in her grandfather's mansion, she is one of the first humans to befriend a Fog Mental Model outside of Blue Steel. In her case, she becomes close friends with Haruna and Kirishima.

It is soon revealed that Makie's ''true'' origins have greater weight in the conflict between the Fog and Humanity.
* ArtificialHuman: She is one of the few surviving Designer Children, who were genetically modified to fit a specific need by the Japanese Government in the trying times after the Fog Blockade. In Makie's case, her role was to design a weapon that could be used by Humanity to fight back against the Fog. She succeeded, with the end result being the Vibration Torpedo.
* ChildProdigy: Helped design the torpedo that has the Fog running scared.
* CompositeCharacter: She gains her older brother Makoto's dependency on special medication to even digest her food in ''Ars Nova''.
* LittleMissBadass: In the manga Makie has been taught some basic martial arts by Lawrence. Her first appearance was [[TheWorfEffect kicking Kyouhei's ass]].
* MoralityPet: Turned Haruna from a war machine into one of the best developed characters of the manga.
* MysteriousWaif: She isn't allowed to travel very far from the mansion she lives in. As a result, she hasn't had much contact with too many people.
* OlderThanTheyLook: Haruna discovers Makie's physical development has been suppressed chemically. She's actually the same age as her brother Makoto but appears to be (and acts) around five years younger.

!!Lawrence Valentine/Toujuurou Osakabe

Makie's overprotective butler. Unknown to Makie, Lawrence is actually [[spoiler:Toujuurou Osakabe, her "grandfather" and creator.]]

In Ars Nova, he is Makie's adopted father and a prominent weapons researcher. [[spoiler:His attempts to defeat the Fog inevitably turns up in failure, largely due to the limitations of humans. He ends up creating Makie in the lab, and with her help, manages to design a torpedo that's capable of defeating Fog ships.]]
* TheAtoner: As the maker of the Designer Children, the weight of all the young lives that had to be sacrificed to succeed in creating them eventually weighs on his conscience. His pampered attitude towards Makie, one of the few left who survived, reflects his resolve in trying to give her a normal childhood.
* BattleButler: Although Makie just knows him as Lawrence, secretly he is...
*** [[spoiler:TheProfessor: Involved in the creation of Makie and the other Design Children and her unseen 'grandfather'.]]
* DiseaseBleach: [[spoiler:His hair turned white as he watched most of the design children die in front of him.]]
* FakingTheDead: [[spoiler:In Ars Nova, he faked his death in an attempt to keep the government from doing things to Makie. While Makie believed he really died, Haruna and Kirishima finds out he was still alive, but bedridden. He does [[KilledOffForReal eventually die]] shortly after meeting the two Fog ship girls however, but not before asking them to watch over Makie, after noticing how attached the girl was to them.]]
* GiveHimANormalLife: What he tried to do with Makie. He mostly succeeded, until the Army [[spoiler:tried to have Makie assassinated, that is]].
* HeroicSacrifice: Stopped the Army from assassinating Makie, but it... [[HeroicSacrifice uh... yeah]].
* OmnidisciplinaryScientist: [[spoiler:In Ars Nova where he was a weapons researcher and geneticist. Unlike in the manga where he was only a geneticist.]]

!!Saori Chihaya

Mother of Gunzou Chihaya. She is currently under house arrest, ostensibly for her own protection.
* DeathByAdaptation: Hinted to have committed suicide in the ''Ars Nova'' anime.
* GildedCage: She's under house arrest in a mansion that's heavily monitored by security cameras. The place is lovely with a huge greenhouse/aviary in the back where she can still do her research on birds and has a domestic staff to handle all the chores, but she's still banned from leaving the property.
* ShipperOnDeck: Ships Takao with her son.

!!Kotono Amaha

The childhood friend of both Gunzo and Sou, she was the valedictorian of their class at the Maritime Institute. She died when the test facilities of the institute caught fire, but her remains have never been found. It was her death that fueled Gunzou's dissatisfaction with the current state of the world, which eventually made him accept Iona's offer of partnership.

[[spoiler:There are increasing signs that she might have been one of Yamato's mental models to begin with, sent to live among humanity to satisfy whatever curiosity the supreme battleship had for humans in general. Notably, her death occurs at about the same time Yamato returns to the fleet with a Mental Model.]]

* TheAce: Her reputation among Gunzo's schoolmates. Sou even calls her "the wall that Gunzou could not overcome".
* ChildhoodFriend: To Gunzou and Sou.
* CynicismCatalyst: Her death was the prime motivator for Gunzo to change the status quo of the world, and ally with Iona.
* PosthumousCharacter: Died in an accident two years prior to the start of the story, however...
** NeverFoundTheBody: ... they never found her body after the fire that killed her.