The following is a list of characters and tropes that apply to them in Arpeggio of Blue Steel. Do note that The Other Darrin 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.
The main characters. On paper an 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.
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.
The Captain of I-401, and he makes most of the tactical decisions of Blue Fleet in general.
- Badass in a Nice Suit: He generally wears a primarily black suit and red shirt when meeting with clients. In Ars Nova he wears the suit all the time.
- Batman Gambit: 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.
- The Captain
- Chick Magnet: Both human girls and Fog ships are attracted to him, though (probably) for different reasons.
- Child Prodigy: He was one of the top students in his class back when he was studying to join the navy.
- Combat Pragmatist: He's willing to do whatever it takes to win a battle. Considering his opponents are nigh-invulnerable warships who gave humans a Curb-Stomp Battle they still haven't recovered from, it's not surprising he's forced to think outside the box with I-401.
- Desperately Looking for a Purpose in Life: 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.
- Disappeared Dad: 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 identical voice (not to mention possessing a Mysterious Waif), drawing comparisons between Gunzou and Lelouch is practically inevitable.
- Intelligence Equals Isolation: At first, during the academy. He still has trouble relating to people but is surprisingly comfortable speaking with Fog Mental Models.
- Oblivious to Love: It's doubtful that he had any idea he had two girls swooning over him during school. One still is, the other died in a terrible fire... maybe
- Red Baron: Called the "Battleship Killer" and "Route Holder" in chapter one.
- The Paragon Always Rebels: 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.
- The Strategist: He comes up with some rather unique tactics during combat to win against his opponents.
- Xanatos Speed Chess: 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.
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.
- Adaptation Dye-Job: She has white hair in the manga, while it has more of a blueish tint to it in the anime.
- Adaptation Personality Change/Character Exaggeration: Iona in the Ars Nova continuity is more of an Emotionless Girl 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.
- Amnesiac Hero: 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.
- Attack Drone: Uses three remotely-controlled airplanes to torpedo Kongou in the manga.
- Barbie Doll Anatomy: During her introduction to Gunzou in the manga, Iona pretty much featured this during her Naked First Impression. Justified as we see her part-way through forming her body and the only part that's finished is her face.
- Emotionless Girl: In the anime.
- Little Miss Snarker: Iona in the manga. At this point, Takao, Hyuuga, and even Ashigara and Hagurou, have been on the receiving end of her snark.
- I Am Who?: 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: 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: 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.
- Iconic Outfit: 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 Zettai Ryouiki.
- Manga: A printed T-shirt (the T-shirt itself is different every time), denim hip shorts, Zettai Ryouiki, and ankle boots.
- My Master, Right or Wrong: 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.
- Mystical White Hair: She has white hair, which hints at her being a Fog ship.
- Rapunzel Hair: She has waist length hair.
- Rei Ayanami Expy: In the anime only.
- Screw the Rules, I'm Doing What's Right!: 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.
- Self-Duplication: She has one main form and several numbered clones running around the submarine, taking care of various tasks.
- Spaceship Girl: 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.
- The Stoic: Moreseo in the anime than the manga.
- Sugar-and-Ice Personality
- Talking to Herself: With her other triplet sisters in the drama CD. In the anime each of the 400-series subs has their own voice actress.
- Undying Loyalty: 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.
The First Mate of I-401, Sou generally provides inventory of their supplies as well as aiding Gunzou with tactical decisions.
- Childhood Friend: He and Gunzou have known each other since elementary school.
- Cool Mask: He has two; the first allows him to interface directly to 401's systems, likely equipped with a Heads-Up Display. 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).
- Mr. Exposition: Particularly in the early chapters as 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.
- Number Two
- The Blank
- The Faceless: Always has his helmet on. He claims it's easier to contain his allergies this way.
- The Graph Shows the Trend: He loves them.
- The Un-Reveal: He's opened the mask only once in flashback but we only see Gunzou's reaction.
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.
- Big Eater: 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!
- Black Dude Dies First: He's noticeably darker than the rest of the cast and his decoy was the first killed at Iwo Jima.
- Cool Shades
- The Generic Guy: 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.
- Hidden Depths: 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.
- Otaku: A mild case, since only him and Iona watch anime aboard the ship.
The Engineer of I-401, she does all the humanly-possible maintenance aboard the ship and keeps Iona's heavily-modified engine running smoothly.
- Cuddle Bug: 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).
- Girlish Pigtails
- Scotty Time: Almost Always ahead of every engine failure, breakdown or last-second power boost needed. Which is really handy, because it happens a lot.
- The Engineer: Of the Mechanic variety.
- Tomboy with a Girly Streak
- Wrench Wench: Comes with being the engineer.
The sonar operator of I-401, she plays the crucial role of locating various hazards outside the sub via sonar.
- Beware the Nice Ones: Oh hell yes. The Japanese special forces found this out the hard way.
- Hime Cut: Befitting of her quiet temperament and ladylike traits.
- Mysterious Past: 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.
- Naked People Are Funny: Once forgot to get dressed when surprised by a combat alert.
- The Quiet One
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.
- Boobs-and-Butt Pose: She is introduced in the Anime opening through this pose.
- Breakout Character: Takao quickly became a fan favorite after her introduction, leading 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
- Cannot Spit It Out: Attempted to make a love confession to Gunzou... and failed miserably.Takao: A maiden's heart is complicated!Hyuuga: Then maybe you shouldn't have installed a maiden plugin!
- Combat Pragmatist: Something she learned from Gunzou
- HeelFace Turn: Runs away from the Fog and joins Blue Steel.
- Heroic Sacrifice: 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. 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.
- In-Series Nickname: Tsundere Heavy Cruiser. Sees regular use by the Yamato-aligned Fog Ships like I-402 and Zuikaku.
- Instant Cosplay Surprise: 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.
- I Want My Beloved to Be Happy: 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.
- Macross Missile Massacre: 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.
- Mid-Season Upgrade: Care of Hyuuga in Cadenza, and one that Takao did not appreciate: a pair of gigantic magma boring drills.
- Rapunzel Hair: Though it is not directly visible because her ponytail is usually put up in a complex corkscrew, when loose her hair reaches her ankles.
- Red and Black and Evil All Over: She's the series Starter Villain, and her ship's sinister red-and-black colour scheme means she looks the part, but she promptly performs a High-HeelFace Turn and turns blue.
- She's Got Legs: More prominently displayed in some of the anime artwork.◊
- Stalker with a Crush: To Gunzou.
- Starter Villain: She's the first Fog warship the I-401 has a proper on-screen battle against. The 'villain' bit doesn't last long, though.
- Themed Aliases: 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.
- Those Two Girls: 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.
- Self-Duplication: Like Iona, she too has several mini models that helps her in doing mundane tasks.
- Unlimited Wardrobe: Like all mental models, she can change clothes as she wishes, but she's one of few who doesn't stick to one set.
- You Gotta Have Blue Hair: She has blue hair.
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.
- Cat Smile: All the time.
- Cleavage Window: Not as evident as with the usual examples, but her Mental model in the Ars Nova anime sports these.
- Excuse Me While I Multitask: Her schtick in Ars Nova. She can quite easily fend off rockets while talking to Kongo across Iwo Jima and talk to Makie while fighting Takao for food.
- Gadgeteer Genius: 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 dock with for a major power boost.
- Genius Bruiser: She commonly acts as The Smart Guy for Blue Steel but make no mistake, she's all but unstoppable in a fight against anyone who's not another Mental Model.
- Genki Girl: Acts this way towards Iona frequently.
- The Glomp: She loves doing this to Iona.
- Heroic Sacrifice: Took Hiei down with her to buy time for Iona's escape. Thanks to just how resilient Union Cores are, they're both Not Quite Dead.
- High-Class Glass: Sports one with a gold frame as part of her mental model
- Hot Scientist: Presents herself as one with her mental model, complete with...
- Labcoat of Science and Medicine: Her signature style. It doubles as a Badass Longcoat and since it's made of nanomaterial she can alter how long it is, which she does purely for dramatic effect.
- Love at First Punch: With 12 corrosive torpedoes.
- Power Fist: Chapter 34 of the manga gives her a pair of huge ones, each bigger than her torso.
- Rocket Punch: The aformentioned power fists.
- Stalker with a Crush: To Iona.
- Shipper on Deck: Ships Gunzou and Takao. Mostly because she wants Gunzou away from her Iona-neesama, so she can have her to herself.
- Those Two Girls: With Takao. Usually butts heads with her, but will nonetheless help her out when needed. Apart from her Shipper on Deck 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).
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.
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.
- Adaptational Curves: Yamato is far bustier in Cadenza than she is in the manga, and shows off a good deal more cleavage.
- Cain and Abel: Despite being the older sister, she's the one who was first offed by Musashi in Cadenza. Temporarily, anyway.
- Death by Adaptation: 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...
- Not Quite Dead: 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.
- Humans Are Special: What she thinks in Cadenza. 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.
- Lady of War
- Mysterious Backer: 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.
- Orcus on His Throne: 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.
- Perpetual Smiler
- Single-Minded Twins: Averted. Unlike Nagato, Yamato's two Mental Models display distinct personalities, with one still acting like prim and proper princess, and the other... acting exactly like Gunzou's dead childhood friend Kotono Amaha.
- The Chessmaster: 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.
- The Ojou
- Troll: In the very non-canon extras included in each manga volume, Yamato takes particular pleasure in trolling her subordinates I-400 and I-402.
- Worthy Opponent: Respects humanity for their strategic skills and will to keep fighting the Fleet of Fog despite the odds.
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.
- Adaptation Personality Change: Let's just say that when one version acts as the "Final Boss" in an arc that spanned several books, while the other not only arrives as THE most powerful member of The Cavalry 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.
- Art Evolution: 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.
- The Cavalry: In Cadenza, where she's the last to arrive and assist Blue Steel in breaking Hiei's blockade.
- Emotionless Girl: 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.
- Establishing Character Moment: 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 ramming them, hinting at the brute force method of solving problems she will exhibit later on.
- Fanservice Pack: In Cadenza, Kongou wears a much more revealing outfit and appears to have larger breasts compared to Ars Nova.
- Graceful Ladies Like Purple / Purple Is Powerful: Imbues elegance of a Proper Lady 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.
- Hime Cut: 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 grows it out) for the full effect.
- Implacable Woman: She becomes extremely obsessed with Iona and attempts to sink her at all costs.
- Licked by the Dog: In the manga, seagulls seem to like her. A lot. Spoofed in the Fog Theater shorts after every chapter.
- Midseason Upgrade:
- 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 Zerg Rush: 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, after realizing that Maya was nothing more than a puppet controlled by I-400 and I-402, she absorbs Maya and converts her ship into a floating Death-Star-like fortress with an oversized Wave Motion Gun.
- My Master, Right or Wrong: 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.
- Pre Ass Kicking One Liner: 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 "The Reason You Suck" Speech 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.
- Ramming Always Works: See Establishing Character Moment. 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, she rams Matsushima with her prow in a last ditch effort to off Gunzou. After the rest her hull was reduced to sinking debris.
- Red Eyes, Take Warning
- Sexy Backless Outfit: What she wears when she makes her triumphant return as part of The Cavalry in Cadenza.
- The Strategist
- The Stoic
- She's Got Legs: The art rarely misses an opportunity to show them off.
- Taking You with Me: When she's finally defeated in chapter 72, Kongou makes a point of destroying the Matsushima before her reactor explodes, possibly killing Gunzou.
- "The Reason You Suck" Speech: Both the giver of, AND the receiving part to, in Ars Nova and the manga.
Kongou: Hiei, let me enlighten you: you use rules for self-discipline. You don't force them on other people.
- 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:
- Took a Level in Badass: 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 to Iona and crew, Kongou has finally had enough and is going all out. Cue her Mid-Season Upgrade and the summoning of her entire fleet with the express purpose of sinking Iona.
- Tragic Keepsake: In Cadenza, it's revealed that she still keeps Maya's piano◊.
- Villainous Breakdown: 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.
- You Are Better Than You Think You Are: 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.
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.
- Badass Longcoat: A rather intimidating All-Encompassing Mantle variant. Its badassery is acknowledged in-universe as well - wearing it gives Haruna a significant confidence-boost. note
- Coat Cape: It covers her entire body, and most of the time only the upper part of her head is visible.
- Chick Magnet: She attracts Makie and Maya very naturally.
- Cry Cute: When her coat is taken away, and when consoling with Makie.
- Defrosting Ice Queen: She's gone from borderline Emotionless Girl to simply The Quiet One. Time will tell if she softens to anyone but Makie or Kirishima, but now that she's joined the naval academy (undercover) she's not even wearing her coat!
- Girlish Pigtails
- HeelFace Turn: Saving Makie definitely counts, though she does not want to join Blue Steel.
- Hidden Heart of Gold: She might seem stoic, though she does not hesitate when Kirishima or Makie is in danger.
- Instant Cosplay Surprise: By Makie.
- Mama Bear: Woe betide those who would harm Makie. Her destruction of an entire army division with armored support was holding back.
- One-Man Army: She goes Dynasty Warriors style on invading human soldiers and vehicles when Makie is threatened.
- Red Oni, Blue Oni: Blue to Kirishima's red.
- Sexy Coat Flashing: A variant in that Makie finds her coat outside of the building that Haruna and Kirishima crashed through and enters to discover Kirishima's core and Haruna's unconscious body clad only in lingerie.
- Sleep Cute
- Sure, Let's Go with That: Makie discovers Youtaro (actually Kirishima) is now mobile:Makie: Are you involved in top-secret government projects and stuff?! Like me?!!Haruna: Er... I... Uh, yes..?
- The Stoic: Most of the time, especially when her mouth is covered by the collar of her coat.
- Not So Stoic: Without her coat, or if her mouth is visible. Not even the coat could hide her emotion when Doctor Osakabe died.
- Themed Aliases: She takes the Osakabe surname 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.
- Took A Level In Bad Ass: After losing her ship body.
- Villainous Breakdown: 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 the Admiralty Code steps in.
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.
- Badass Longcoat: In the manga.
- Bare Your Midriff: Her original, pre-sinking outfit in the manga was a Badass Longcoat 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.
- Butt-Monkey: Poor Kirishima often gets the short end of jokes as Yotarou the stuffed bear.
- Expressive Mask: Often, as Yotarou.
- Fashionable Asymmetry: 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.
- Jerk with a Heart of Gold: The Humiliation Conga 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.
- Large Ham
- No Kill Like Overkill: Used to love this trope. The 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.
- Pintsized Powerhouse: 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. 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.
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).
- Broken Record: 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 fifty-two hours non-stop. She could of course just have been exaggerating.
- Butt-Monkey: She gets easily hacked by the other Mental Models.
- Death by Adaptation: In the Ars Nova anime. Her ship body is even absorbed into Kongou during the finale.
- Genki Girl: Most of the time. 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.
- Madness Mantra: 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 her mind is wiped by the I-400 twins and left to guard/annoy Kongou.
- More Dakka: It's clear that the Fog like this trope, but she likes to take it to a to a completely different level.It's a CARNIVAL! (shoots everything)
- Perky Female Minion: Her current occupation under Haruna which she's found very enjoyable.
- Plucky Comic Relief: 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.
- Self-Duplication: Uses her mini models as an orchestra.
Battleship of the Fleet of Fog and subordinate to Kongou, leader of the self-governing body "Student Council" formed with the Myoukou-class cruisers.
- Composite Character: 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.
- The Dragon: To Kongou. To Musashi in the movies.
- Oh, Crap!: In Cadenza, she does not take Kongou's arrival as one of Blue Steel's reinforcements well.
- Order Versus Chaos: She believes the Fleet should be orderly and not chaotic which is why she hates Hyuga.
- The Rival: 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 Wave Motion Gun significantly off-axis. The system is apparently unique to her.
- Shut Up, Kirk!: In DC, she verbally stonewalls Iona's attempts at trying to find a non-violent resolution with her.
- Student Council President: She and her own personal squadron wear matching Student council uniforms.
- Zettai Ryouiki: A solid Type A.
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.
- Cold Sniper: Calm, collected, and specialized in delivering one-hit-kill shots.
- Eyepatch of Power: Linked to her main cannons as a targeting display, it's otherwise decorative and removable.
- Fashionable Asymmetry: Her knee-socks are of different lengths. She and Haguro both wear a single armoured bracer in the manner of Japanese archers note The hemlines of all "Student Council" jackets (save Hiei herself) are longer on the left side.
- The Dragon: To Hiei.
- You Gotta Have Light Purple Hair
Sister ship of Myoukou, has top-notch sonar and communications gear and serves as the ears of Hiei's "Student Council".
- Necessary Drawback: 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.
- Recursive Ammo: 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.
- Red Oni, Blue Oni: The Blue to Ashigara's Red.
- The Quiet One: Has a very muted personality compared with her sisters.
- The Smart Guy: Is constantly asking Ashigara to slow down and study the data before charging into combat.
- You Gotta Have Lime Green Hair
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.
- Adaptational Badass: 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 Kantai Collection's Shimakaze, of all people, in the Ars Nova Cadenza movie.
- HeelFace Turn: For the time being, as Iona's "guests" she's stuck helping with the extra bridge duties alongside Ashigara.
- Humiliation Conga: 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.
- Necessary Drawback: 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.
- Token Mini-Moe: 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.
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.
- Actually Pretty Funny: After getting beaned in the face with a torpedo, Ashigara floats stunned to the surface before cracking up with laughter.
- Adaptational Badass: 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.
- Blood Knight: 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.
- Boisterous Bruiser: 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 exaggerates her personality to full Genki Girl levels of hyperactivity.
- Butt-Monkey: 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.
- Cute Little Fangs: Highlighting her aggressive nature, she sports a pair of fangs.
- Genki Girl: 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.
- HeelFace Turn: Time will tell if it will stick, but for now both she and Haguro are assisting with the bridge duties onboard Iona.
- Hair Decorations: She wears a pair of stylised wolf hair clips above her ears. Along with her Cute Little Fangs it's referencing her Real Life counterpart's nickname "The Hungry Wolf".
- Hime Cut: With bonus Ojou Ringlets at the ends of her long side locks. Amusingly, common tropes associated with this hairstyle don't apply to Ashigara.
- O.O.C. Is Serious Business: Ashigara drops the genki girl act entirely when Iona decides to try and recover the Matsushima in the wake of the Mutual Kill 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.
- Red Oni, Blue Oni: The Red to Nachi's Blue.
- Taking the Bullet: 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.
- Worthy Opponent:
- Wants to be this for Iona, believing in the Fair Fight. 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.
IseBattleship 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.
- All for Nothing: 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.
- The Dragon: For Kongou, after Hiei gets taken out by Hyuuga.
- The Dreaded: Hyuuga is terrified of her sister. Given her obsessive/possessive behaviour, this is probably well-founded.
- The Ghost: Was only vaguely referred to prior to her introduction in Chapter 63.
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, Musashi, who in Ars Nova Cadenza was revealed to have usurped the Admiralty Code through sinking her sister ship Yamato.
- Adaptational Villainy: 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.
- Death by Adaptation: Is sunk by Iona in the Ars Nova anime.
- I Have the High Ground: I-400 prefers observing Haruna and company from rooftops and other elevated vantage points.
- Qipao: Wears a shirt styled after one.
- The Stoic: 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).
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.
- Adaptational Villainy: See I-400's entry.
- Death by Adaptation: See I-400's entry.
- HeelFace Door-Slam: In the anime at least, she only start to show a tiny bit of emotion just before she got hit for shielding her sister.
- Little Miss Snarker: 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.
- Team Mom: 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.
- The Chessmaster: 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 just to see what will happen next.
- Finishing Each Other's Sentences: Her two mental models do this.
- Single-Minded Twins: 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.
- Yamato Nadeshiko: 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.
- Big Ol' Eyebrows: Considerably thicker than average for Mental Models, when you can see them behind her bangs, of course.
- Friend in the Black Market: 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. Rod and reel, usually.
- Kind Hearted Cat Lover: 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.
- Non-Indicative Name: Zuikaku has been 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.
- The Pirates Who Don't Do Anything: 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.
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.
- Cool Shades: Wears a black pair upon reappearing as Admiral of the Scarlet Fleet.
- FaceHeel Turn: Was a former war hero who captured the I-401. Now he's one of the Fleet of Fog commanders.
- Death by Adaptation: 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.
- Reasonable Authority Figure: 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. In truth, his subordinates, who didn't like to negotiate, killed him during a mutiny.
- Utopia Justifies the Means: 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.
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.
- Adaptational Villainy: 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 Big Bad AND has it in for Humanity as a whole.
- Big Bad: For the Cadenza movie.
- Cain and Abel: Inverted. As the younger sibling, it's Musashi who sends Yamato into the depths of the Bering Sea.
- Entertainingly Wrong: She's utterly convinced throughout Cadenza that Yamato's been pulling the strings behind Blue Steel's actions, and using "Iona" as a mask. Unfortunately when Iona reveals that she's her own person, and Yamato hasn't been actively guiding her, Musashi well and truly loses it.
- Eyes Always Shut: Through the manga and most of Cadenza. When she does open her eyes in the movie, it's usually for something important.
- Humans Are Bastards: Her motivating factor throughout Cadenza: that Humanity as a whole could not be trusted, and would be better off wiped out. 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.
- Hoist by Their Own Petard: Her own Mirror Ring system is used in the finale of Cadenza to defeat her once and for all, 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. This is exactly how she is finished off in the end.
- Insistent Terminology: She keeps on calling Iona "Yamato's Doll" in Cadenza. Because she's convinced that Yamato's personality is secretly hiding underneath Iona's facade. Except she's very VERY wrong.
- Nice Hat: In the manga she owns an astrakhan, while in Cadenza she wears a black mohair beret with a black rose pinned to one side.
- Pretty in Mink: We are first introduced to Musashi in the manga wearing an astrakhan hat and a fur-lined mantle.
- Villainous Breakdown: In Cadenza, Musashi essentially breaks down in a massive temper tantrum when she learns through Iona who is speaking with Yamato's memories that, despite everything she's done, Yamato still loves her as her dearest sister.
- Who Wears Short Shorts?: Her outfit for Cadenza, combined with the obligatory Zettai Ryouiki.
U-2501Fleet of Fog submarine European Fleet under the command of Zordan Stark and his human crew. 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.
- Cry Cute: When Zordan orders her to cancel her mental model.
- Does Not Like Shoes: Dances barefoot on her deck while she has the ability to do so.
- No-Sell: The Mirror-Ring System, which is supposed to be exclusive to Yamato and Musashi, lets U-2501 deflect super-heavy cannon shots.
- Token Mini-Moe: Her mental model takes the form of an adorable child, a marked contrast to her crew who are all in their mid/late teens.
- Undying Loyalty: U-2501 is completely dedicated to Zordan, whom she considers infallible, despite the open disdain he has shown towards her.
Zordan StarkCaptain 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.
- Combat Pragmatist
- Germanic Efficiency: 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.
- Evil Counterpart: 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.
- Smug Snake
- The Only One Allowed to Defeat You: 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.
- We Can Rule Together: After cornering the 401 and its crew, Zordan suggests Chihaya to join the Fleet of Fog under his boss, Chihaya's father.
- Wolfpack Boss: Appropriately, Zordan's strategy. Alongside the U-2501, he also commands a force of automated midget subs known as the 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.
BismarckThe first Fog battleship sighted by humans. Last witness of the Admiralty Code, Flagship of the Fog's European Fleet. Currently allied with Chihaya Shouzou's Scarlet Fleet to find the Admiralty Code but if the alliance will last is doubtful.
RepulseA 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.
- Boobs of Steel: 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 weaker armor than a true battleship and an even weaker sense of confidence.
- Prehensile Hair: A variation: it's not her actual hair, but Repulse has a pair of long ribbons on her hat which function the same way.
- Meido: Not only has the uniform, but quite literally sweeps up damage with nanomaterial brooms.
- Luminescent Blush: Easily flustered and embarrassed, especially whenever Vampire brings up the potential of working with humans.
- Screw This, I'm Outta Here!: Had to abandon her patrol route after Prince of Wales decided she was disobeying orders.
VampireRepulse'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 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.
- Cute Little Fangs: As befits her namesake theme. Appropriately for a vampire, 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.
- Servile Snarker: Vampire takes every opportunity to belittle Repulse's competency, but it's obvious that she's loyal to cruiser all the same.
LexingtonFlagship of a detachment from the North American fleet, come to "aid" Kongou in Blue Steel's destruction.
- Badass Bookworm: 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.
- Not a Morning Person
- Phenotype Stereotype: Blond, light-colored (probably blue) eyes, freckles. Definitely from the American fleet.
- Shout-Out: Lexington's sub units, rather than looking like miniature versions of herself (as seen with Iona and Takao), look like Robbie the Robot.
Supporting Human Characters
MitsumineCurrent 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.
- Number One: Was formerly Kita's XO when they took part in the Great Naval Battle.
- Friendly Enemy: Views Kita as this; while they're bitter political opponents, he still has affection for his former captain.
- Genius Cripple: 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.
- Good Is Not Soft: See the Chains of Commanding, below.
- Machine Monotone: Possibly. He's yet to be voiced by an actor, but his speech bubbles are shaped like those used for radio communications, so his voice is certainly artificial.
- Reasonable Authority Figure
- The Chains of Commanding: 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 KitaDiet member and likely the next Prime Minister of the Central District.
- The Captain: Was formerly a JMSDF destroyer skipper, and acquainted with Gunzou's father.
- Friendly Enemy: 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.
- Honor Before Reason: 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.
- No, Mr. Bond, I Expect You to Dine: Gunzou and his crew are treated to this in episode 3/Chapter 8. During dinner (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 not the (strained) civility).
- Realpolitik: Prime Minister Mitsumine and Asst. Secretary Kamikage are his primary opponents in the power struggle within the Japanese government until Kita resigns to save face for the Army.
Kamikage RyujirouAssistant 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.
- Good Is Not Nice: 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 ''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.
- Reasonable Authority Figure: 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.
- The Chessmaster: Has a lot of assets to move around the board, these only grow after his promotion. All for Japan.
- The Strategist: As part of his job in the Ministry of Defense.
Cruz HerderOne of the United States Marines stationed in Japan before the fog blockade now part of the Japanese Navy as a special forces detachment.
- Badass Normal: He's yet to engage in combat but interactions with other characters detail his professional reputation as one.
- Deadpan Snarker: His casual and often irreverent mannerisms contrast sharply with the much more uptight Kamikage, his primary contact and ally in the Ministry of Defense.
- Older Than He Looks: 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 KomakiCaptain 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.
- Badass Normal: 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. Willing to intervene in the escape of Repulse and Vampire into the Pacific.
- Hotblooded Sideburns: An understated, well-trimmed example, but they do go all the way to his jawline.
Former Sonar operator of I-401. Transfers to the Hakugei because of her experience in Blue Steel.
- All Love Is Unrequited: 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.
- Love Cannot Overcome: 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.
- Artificial Human
- Creepy Child
- Dude Looks Like a Lady
- Team Switzerland: Is willing to support either the Japanese government or the Fleet of Fog as long as Hokkaido benefits from the alliance.
- The Leader: Was genetically engineered to be a capable leader without humans flaws like corruption or greed.
- The Stoic: Neither is he capable of strong emotions, being engineered to be objective and dispassionate. His concern for Makie and by extension Haruna, Kirishima and Maya is noted by himself as deeply uncharacteristic.
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.
- Artificial Human: 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.
- Child Prodigy: Helped design the torpedo that has the Fog running scared.
- Composite Character: She gains her older brother Makoto's dependency on special medication to even digest her food in Ars Nova.
- Little Miss Badass: In the manga Makie has been taught some basic martial arts by Lawrence. Her first appearance was kicking Kyouhei's ass.
- Morality Pet: Turned Haruna from a war machine into one of the best developed characters of the manga.
- Mysterious Waif: 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.
- Older Than They Look: 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 Toujuurou Osakabe, her "grandfather" and creator.
In Ars Nova, he is Makie's adopted father and a prominent weapons researcher. 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.
- The Atoner: 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.
- Battle Butler: Although Makie just knows him as Lawrence, secretly he is...
- The Professor: Involved in the creation of Makie and the other Design Children and her unseen 'grandfather'.
- Disease Bleach: His hair turned white as he watched most of the design children die in front of him.
- Faking the Dead: 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 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.
- Give Him a Normal Life: What he tried to do with Makie. He mostly succeeded, until the Army tried to have Makie assassinated, that is.
- Heroic Sacrifice: Stopped the Army from assassinating Makie, but it... uh... yeah.
- Omnidisciplinary Scientist: In Ars Nova where he was a weapons researcher and geneticist. Unlike in the manga where he was only a geneticist.
Mother of Gunzou Chihaya. She is currently under house arrest, ostensibly for her own protection.
- Death by Adaptation: Hinted to have committed suicide in the Ars Nova anime.
- Gilded Cage: 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.
- Shipper on Deck: Ships Takao with her son.
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.
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.
- The Ace: Her reputation among Gunzo's schoolmates. Sou even calls her "the wall that Gunzou could not overcome".
- Childhood Friend: To Gunzou and Sou.
- Cynicism Catalyst: Her death was the prime motivator for Gunzo to change the status quo of the world, and ally with Iona.
- Posthumous Character: Died in an accident two years prior to the start of the story, however...
- Never Found the Body: ... they never found her body after the fire that killed her.