The Character Sheet for the light novel series The Ending Chronicle.
Beware of Unmarked Spoilers.
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Team Leviathan
As a Group
- Gender-Equal Ensemble: The team is made by three guys (Sayama, Izumo, and Dan) and three girls (Shinjou, Mikage, and Heo). Well, one of the girls is physically male half the time, but her gender identity is always female.
- Ragtag Bunch of Misfits: We have a self-proclaimed villain with a utter lack of common sense and the delusion that he's perfectly normal, a sniper whose body is "special" because she's a girl or a boy depending on the time of the day, a lazy and perverted student council president, said president's hyper-violent girlfriend powered with Super-Strength, a Robot Girl slowly evolving into a human, a grumpy Japanese-American everyone calls a delinquent, and an American girl with a sensorial link to a mechanical dragon.
- True Companions: The team engages in a lot of arguments and teasing, but they're all friends who fight together.
Mikoto Sayama
Voiced by: Daisuke Hirakawa (Drama CD)
The main protagonist. Sayama is the eccentric Taka-Akita Academy's Student Council vice-president. By the will of his deceased grandfather Kaoru Sayama, he was designated as the representative of Low-Gear in the Leviathan Road negotiations. He becomes Team Leviathan representative, negotiator and leader. He has been raised from childhood to be a superb villain to perform necessary evils. Currently having no relatives, the Tamiya household looks after him, but Sayama keeps distance from them because they only treat him with respect because of a debt they owe to his deceased grandfather.
- Always Save the Girl: He outright states that Shinjou is a higher priority to him than the world. When questioned the logic behind it, Sayama claims that he needs to be with Shinjou in order to save the world. Therefore, keeping him away from Shinjou is the same as trying to destroy the world.
- Anti-Hero: Sayama is certainly one of the good guys, yet he calls himself a villain who will resort to any dirty methods necessary to crush his enemies.
- Badass in a Nice Suit: Sayama almost always wears a suit and tie and has been trained in combat by his grandfather and Ryuutetsu Hiba.
- Battle Couple: With Shinjou. Sayama fights with his martial arts training and swordsmanship while Shinjou helps him with her sniper skills.
- Bunny-Ears Lawyer: Despite all his eccentricities, Sayama is a very sharp and skilled negotiator.
- Cassette Craze: He carries around portable recorders that he likes to use to record Shinjou saying Innocent Innuendos. He also has several recorder versions such as the indoor version, the outdoor version, the adventure version, happy version, demon king version, and more.
- Chastity Couple: With Shinjou. Sayama openly admits he wants sex with her very much, but abstains from doing so out of concern for the development of her body. After Shinjou's body develops to the point of menstruating, Sayama and Shinjou consummate their relationship in the final volume.
- Chivalrous Pervert: As much of a shameless pervert he can be to Shinjou, he does care about her well-being and feelings very much. Even though he's very open about wanting to have sex with her, he refrains himself from doing it until she grows accustomed with her own Sex Shifting body.
- Cloudcuckoolander: His thought process is really odd and hard to follow.
- The Comically Serious: He always keeps the same serious expression even in his most eccentric moments.
- Crazy-Prepared: Sayama seems to be prepared for any kind of situation he might encounter. He carries around a screwdriver, a wrench set, a set containing a stethoscope and portable recorder just in case. He also keeps underwear for Shinjou with him in case of an emergency.
- Crotch-Grab Sex Check: He makes sure that "Setsu" is a boy by grabbing and pulling his penis in the bathroom. Later, he undresses and grabs "Sadame's" crotch to confirm she's a girl and not "Setsu" in disguise. Sayama fails to even see the possibility that Shinjou is a Sex Shifter for quite some time, but he later figures it out.
- Cuckoosnarker: Sayama might have a very peculiar way of thinking and behaving, but he's quick to make sarcastic quips at those around him. This is one of the first signs that he's much sharper than he may appear to be.
- Deadpan Snarker: He always takes the chance to make snarky comments about those around him.
- Desperately Looking for a Purpose in Life: At the end of the series, Sayama admits that unlike his teammates, he has nothing he wants to do himself after the Leviathan Road ends. The only thing he has ever gotten serious about is the Leviathan Road, which is basically nothing but him cleaning up the messes left behind by his grandfather and father. Shinjou promises she will help Sayama find what is it he wants to do in the future and he's fine with just that.
- The Dulcinea Effect: He readily jumps to save Shinjou from a werewolf when he doesn't even know her yet.
- Eating the Eye Candy: Sayama takes every chance he gets to ogle at Shinjou's "eroundic" butt. He even calls Shinjou the "butt spirit".
- From Roommates to Romance: Sayama is attracted to Shinjou from their first meeting and she becomes his dorm roommate under the fake identity of her "twin brother" Setsu. It doesn't take long for them to become a couple.
- Genre Blindness: Throughout the second arc, despite already knowing he lives in a world that keeps hidden survivors of alternate worlds, most of which are fantastic creatures like dragons, monsters and even gods, he completely fails to consider the possibility that Shinjou is a Sex Shifter until near the end of the arc.
- Guile Hero: He usually resorts to manipulation and blackmail to succeed in the Leviathan Road negotiations.
- Heroic BSoD: After Hajji reveals Sayama's mother died protecting him instead of trying to kill him as Sayama always had thought, Sayama suffers such a serious mental shock that his chest pains become unbearable and he collapses on the spot. It's thanks to Shinjou's words of encouragement that Sayama is able to pull through.
- Hilariously Abusive Childhood: Sayama's childhood involved him getting repeatedly beaten up and abused by his grandfather in absurd ways, as well as almost getting killed by his martial arts teacher multiple times.
- Hope Bringer: After learning to accept his own past, Sayama decides he will be a source of inspiration and hope to those who are still dragged down by their pasts so he can show them the path to move ahead.
- Idiot Hero: Sayama is very intelligent, but his utter lack of common sense leads to him acting in pretty stupid ways that give him fame as an idiot.
- If It's You, It's Okay: Sayama says he's not into boys, unless that boy is Shinjou.
- It's All About Me: He calls himself the center of the universe.
- Jerk with a Heart of Gold: He's arrogant, self-centered, rude, snarky and manipulative, but ultimately a good-natured and well-meaning guy.
- Large Ham: His general attitude is over-the-top and full of charisma. He loves to strike poses for no reason and give powerful speeches to inspire his allies.
- The Leader: A mix of the The Mastermind and Type Charismatic. He leads Team Leviathan in their negotiations and fights, makes most of the major decisions of what to do in the Leviathan Road and despite his general weirdness, he knows to give damn good motivational speeches for his team.
- Left-Handed Mirror: Sayama is left-handed while his partner and girlfriend Shinjou is right-handed. This fits into the theme of them being opposites which the novel frequently emphasizes.
- Lovable Sex Maniac: A good part of Sayama's interactions with Shinjou have him making all sort of perverted remarks, particularly about her butt. He also likes to undress, grope and peep at her whenever he can.
- Love at First Sight: He immediately falls head over heels for Shinjou the first time he sees her.
- Necessarily Evil: His grandfather raised him to be a villain who would perform necessary evils in order to destroy his evil enemies. However, Sayama doesn't know when the abilities he carries are truly necessary since his grandfather didn't teach him when to get serious.
- No Sense of Personal Space: He tends to get too uncomfortably touchy-feely around Shinjou.
- No Social Skills: He usually doesn't seem to understand what is proper to do when interacting with people, says things in a blunt manner at the worst possible moments and completely fails at reading the mood.
- Oblivious to His Own Description: Every time he's referred to as the eccentric, self-centered idiot he is, Sayama doesn't catch on they're talking about him. He's also perplexed when Shinjou says he's just like his grandfather, as Sayama thinks there's no way he's similar to that "self-centered old man who did nothing but eloquently mock others".
- Omniglot: His grandfather taught him 13 different languages.
- Only Sane Man: Subverted. He believes himself to be this, but he's really just as weird as everyone around him, if not more.
- Opposites Attract: With Shinjou. He's an arrogant, eccentric Jerk with a Heart of Gold and she's a sweet, sensible Nice Girl. One of the reasons why Sayama is attracted to Shinjou is because he views her as his opposite.
- Ordinary High-School Student: He lives as a rather normal high school student until he finds out about the Concept War and that his deceased grandfather left him the right to be the representative of Low-Gear in the negotiations for the Leviathan Road.
- Pay Evil unto Evil: Sayama was taught that in order to destroy evil, he would have to do some evil deeds himself.
- Pragmatic Hero: He often resorts to ruthless tactics and blackmail to defeat his enemies.
- Raised by Grandparents: He was raised by his adoptive grandfather after his parents died when he was young.
- Rude Hero, Nice Sidekick: The Rude Hero to Shinjou's Nice Sidekick. Sayama is a self-proclaimed villain who is willing to do some "evil" in order to defeat his enemies, not to mention he's also a self-centered jerk who enjoys insulting and mocking those around him. His partner Shinjou, on the other hand, is so gentle and compassionate that she refuses to harm her enemies. In fact, Sayama chooses Shinjou as his partner because he's "wrong" and she's "right".
- Second Year Protagonist: Sayama is a second-year high school student and he leads the Team Leviathan which is made by students of his same year, seniors, and a junior freshman.
- Sharp-Dressed Man: He likes to wear suits, so when not wearing the school uniform he usually wear a three-piece suit.
- Significant Birth Date: Sayama's birthday is December 24th, which fits into the Christmas and Christianity symbolism of the series. Yukio believed that Sayama and Shinjou being born on Christmas Eve was a sign of the birth of two holy people.
- Single-Target Sexuality: A blatant Shinjou-sexual. He feels equally attracted to Shinjou's female and male forms.
- Sophisticated as Hell: He always speaks to people in a formal and polite manner with several insults and snarky comments mixed in.
- The Spock: Sayama takes the side of reason and objectivity when dealing with the conflict against Hajji and later Mikoku regarding all the losses and deaths of the past. Sayama argues with them that it's wrong to become blinded by feelings of grief and all the survivors of other Gears need to look into the future instead of obsessing over what they lost.
- Stalker with a Crush: Towards Shinjou. He keeps a digital recorder where he's constantly listening to her voice. He also has an entire album dedicated to her as well as his own set of Shinjou-themed merchandise which includes posters and a body pillow made from photos of Shinjou he took in secret. When Shinjou calls what he does stalking, Sayama claims that if Shinjou isn't with him all the time, the universe will fall out of balance and the world will end.
- Stalking is Love: Shinjou is only mildly annoyed by Sayama's creepy stalkerish tendencies towards her, which are all Played for Laughs anyway. The series depicts Sayama as "quirky" yet devoted suitor and Shinjou falls deeply in love with him.
- The Stoic: The expression on his face rarely changes, even in the most extreme and weird situations.
- Sugar-and-Ice Personality: He acts formal, aloof and distant in front of everyone. His sugary side seems to be reserved for Shinjou.
- Take a Third Option: When Shinjou asks him to either choose Sadame or Setsu, Sayama tells her he can't choose one of her false identities; instead he's choosing her real self, Sadagiri.
- Too Kinky to Torture: He very much enjoys physical abuse if it comes from Shinjou.
- Trauma Button: Every time he remembers his family he suffers from symptoms similar to an angina, causing severe chest pains that sometimes even forces him to his knees. This is triggered by the trauma of his mother suffocating him as part of her alleged Murder-Suicide attempt. As a result, the topic of his family in general is a major source of stress for Sayama.
- Tsurime Eyes: His characteristic sharp eyes, a reflection of his arrogant and confident nature.
- Understanding Boyfriend: Shinjou at first feels conflicted about revealing the truth of her body to Sayama, because she fears Sayama will hate her if he finds out. Once the truth comes out, Sayama has no problem with Shinjou being a Sex Shifter because he loves Shinjou just for being Shinjou.
- Vitriolic Best Buds: With Izumo. They're pretty good friends, leaving aside their constant exchange of insults.
- What You Are in the Dark: During his visit to the study of Tenkyou Kinugasa, Sayama is tempted to allow the traumatizing memory of his mother's supposed attempt to suffocate him to death to be extracted from his memory. Sayama does believe that getting rid of that memory would make life easier for him and he wouldn't have to worry Shinjou as much, but he would be denying a part of himself and his own suffering with it. Sayama chooses to keep the memory, claiming that enduring that trauma allows him to rise above others and become stronger.
Sadagiri "Sadame/Setsu" Shinjou
Voiced by: Rie Kugimiya (Drama CD)
The main heroine. Shinjou is a mysterious girl assigned to the Team Leviathan. Having lost her memory, she does not remember where she came from or her own parents. She joins the Leviathan Road to find information about her past. For some reason, her body changes sex from day to night, which is why she doesn't know from which Gear she comes from. To hide the special condition of her body, she lives alternatively under the identities of the twins Sadame and Setsu. Under the identity of her own twin brother, Shinjou becomes Sayama's roommate and later assumes the position of Taka-Akita Academy's Student Council secretary.
- Action Girl: As she adapts to the battlefield, she becomes an efficient gunner.
- Alliterative Name: Sadagiri Shinjou. It also applies for her false names Sadame and Setsu.
- Amnesiac Hero: She has no memories from before she was 6 years old. She joins the Leviathan Road to find information about her past and her parents. Her only clues are her name, a men's ring in her right hand's middle finger and the memory of the Silent Night song.
- Attractive Bent-Gender: Shinjou looks cute in both genders and Sayama finds her very attractive, both as a girl and as a boy.
- Battle Couple: In battle, she supports Sayama by shooting the opponents he doesn't have time to hit.
- Born in the Wrong Century: It's often pointed out Shinjou behaves like someone from the Showa era and she's very ignorant of more modern customs and pastimes. She doesn't know videogames can be played on TV, for example. Her peculiar upbringing at UCAT is to blame for this, with Ooshiro admitting they mostly gave her hand-me-downs when growing up.
- Bully Magnet: The final volume mentions Shinjou was bullied at kindergarten for wanting to be a girl despite her body being physically male during daytime.
- Character Signature Song: She often sings the Christmas carol "Silent Night".
- Chastity Couple: With Sayama. They become a couple as early as the second arc, but Sayama insists they should refrain themselves from having sex out of concern for Shinjou's body. They finally do the deed in the final volume.
- Child of Two Worlds: Shinjou is the child of a Low-Gear woman and a Top-Gear man, who were opposite-gender counterparts of each other.
- Cloudcuckoolander's Minder: She somehow puts up with Sayama's craziness and acts as a stopper for his eccentric actions.
- The Conscience: Sayama basically appoints her as his moral compass, leaving it up to her to put the brakes on his "villainy" if it goes overboard.
- Country Mouse: Having grown up in the mountains of Okutama, Shinjou is quite clueless and naive about the modern life in the big city.
- Cry into Chest: She cries into Sayama's chest when she breaks down and tells him she doesn't want to keep lying to him, even though she fears he will hate her if she reveals her lie to him.
- Deuteragonist: Shinjou's prominence is second only to Sayama and the secrets of her origins are key to the biggest mysteries in the story.
- Fake Twin Gambit: The Half-Identical Twins Sadame and Setsu are identities she uses to hide the fact that she's a Sex Shifter.
- First Period Panic: Inverted. After confirming Yukio Shinjou was her mother, Shinjou gets her first period and feels relieved to discover her body can menstruate despite her being a Sex Shifter.
- Flowers of Nature: After the negotiations with 4th-Gear are finished, Shinjou keeps the flower that contains the tree serpent Mukiti's will in her hair.
- Foil: To Sayama, in accordance to being his opposite. Sayama is serious, full of himself, and lacking in common sense, Shinjou is naïve, unconfident, and sensible. While both lost their parents at a young age, Sayama doesn't hold their memory dearly and he experiences physical pain whenever he's reminded of his family, on the other hand Shinjou lost her memory of her parents and actively wants to learn about them. Sayama is a self-proclaimed villain with no qualms for using dirty methods, while Shinjou is morally good and honest to the core.
- Friendly Sniper: While she's a highly skilled sniper, Shinjou is a very sweet-tempered girl who hates having to shoot people, which is why she asked to have her Ex-St designed to not cause any more damage than she wishes for.
- From Roommates to Romance: After being enrolled as a male student, Shinjou becomes Sayama's dorm roommate and they become a couple in Volume 2-B.
- Gender Bender Angst: Shinjou's body changes sex every half a day, and she goes through several complications to keep people from finding out her unique condition. She's initially very uncomfortable and insecure about her body's unstable physical sex, but she starts feeling more at ease after Sayama and her friends accept her.
- Godiva Hair: In Volume 2-B, there's an illustration of a bare-chested Shinjou with her hair covering her breasts.
- Hair Color Dissonance: Her hair color is described as black in the light novels, but illustrations portray it as purplish blue.
- The Lancer: She backs up Sayama at all times and as his opposite, she naturally acts as his foil.
- Living Emotional Crutch: Shinjou provides Sayama with essential emotional support and she's the only person who can relieve his chest pains whenever he's faced with the topic of his parents. Sayama states that he can endure anything if Shinjou is there to comfort him.
- Long-Range Fighter: She's the team sniper, specializing in shooting blasts and providing support from the distance.
- Meaningful Name: Shinjou's real name Sadagiri means "cut life from destiny". Shinjou doesn't like it since she thinks it's a bad omen, but Sayama convinces her that her name's real meaning is to "cut away the bonds of destiny, freeing life".
- Mistaken for Gay: A Running Gag with her and Sayama. Shinjou is only known as "Setsu" at school and thanks to her clearly close relationship with Sayama coupled with being caught in some suggestive situations, they have gained a reputation as a "hardcore gay couple" across the campus. It's Played With since whilst Shinjou identifies as female, her body is physically male during daytime hours and Sayama feels attracted to her male body as much as the female one.
- Morality Chain: Part of her role as Sayama's counterbalance. Sayama wants her to keep him from taking his evil too far and let him know when his evil is truly necessary.
- Most Writers Are Writers: Shinjou wants to be a writer and she's writing a novel based on the events of the series.
- Ms. Fanservice: Shinjou has the largest number of nude scenes out of any character in the series. The novel features multiple illustrations of her naked body, including her breasts and butt for her sex scene with Sayama in the final volume.
- Naïve Newcomer: Shinjou had never fought at the front lines until she joined Team Leviathan. Her lack of experience and naivete gives her great trouble.
- Necktie Leash: She usually strangles Sayama with his own tie when he gets her annoyed.
- Nice Girl: She's sweet, polite and selfless.
- Nighttime Transformation: The change from day to night triggers Shinjou's Sex Shifter transformation. At 6 AM, she turns into "Setsu" (boy), at 6 PM she turns into "Sadame" (girl).
- No Periods, Period: Played With. Shinjou mentions she hasn't had her period yet and gets stomachaches at the end of every month in place of it. Sayama theorizes this is caused by Shinjou's reluctance to accept her Sex Shifter body. Eventually, Shinjou finally starts menstruating after she gets a confirmation that her mother was Yukio Shinjou.
- Opposites Attract: With Sayama. She's a sweet, sensible Nice Girl and he's an arrogant, eccentric Jerk with a Heart of Gold.
- Oxymoronic Being: Shinjou is the child of the marriage between the female Yukio Shinjou from Low-Gear and the male Yukio Shinjou from Top-Gear. Because of this, her body is influenced by positive and negative concepts at the same time, and the contradiction is represented by her recurrent sex change.
- Quest for Identity: Shinjou is unable to recall anything about her origins and her family. Her main goal is to find out who she is, where she came from and who her parents were.
- Reluctant Fanservice Girl: To her dismay and embarrassment, she usually ends up losing her clothes and/or getting into compromising situations with Sayama.
- Reluctant Warrior: She really hates fighting. She only joined Team Leviathan to find out about her past.
- Rescue Introduction: Her first appearance in the main storyline has Sayama coming to her rescue when she's fighting a werewolf from 1st-Gear.
- Rescue Romance: It's Sayama repeatedly coming to save her from danger what leads her to fall in love with him.
- Rude Hero, Nice Sidekick: The Nice Sidekick to Sayama's Rude Hero. As Sayama's counterbalance, the gentle Shinjou represents the "good" that keeps the self-proclaimed villain Sayama from taking his "evil" too far and bring out the best of him.
- Sex Shifter: Shinjou's body changes sex from day to night; she's a boy during the day and a girl during the night. Shinjou's mother was from Low-Gear and married the male version of herself from Top-Gear. As a result, Shinjou's body is influenced by both positive and negative concepts and her sex changes to represent the contradiction.
- Showgirl Skirt: Her armored UCAT uniform has a skirt divided into three pieces at the back and both sides, only leaving the front of her legs uncovered.
- Significant Birth Date: Same as Sayama, Shinjou was born on Christmas Eve, connecting to the whole Christmas and Christianity thematic that's so relevant in the series. Sayama outright calls her a child of God at one point.
- Skilled, but Naive: It's said Shinjou had excellent scores in training and her marksmanship while providing covering fire from the rear guard was good, but when put to fight in the front lines as a member of the Team Leviathan, Shinjou's inexperience and reluctance to fight keeps her from doing a good job.
- Small Girl, Big Gun: Her Cowling Staff Ex-St can morph into a large cannon.
- Sobriquet Sex Switch: She calls herself "Sadame" in her female form and "Setsu" in her male form. These names are made from the characters of her real name, Sadagiri; Sadame is written like Sada (運) and Setsu is written like Giri (切).
- Straight Man: She's usually the one to tolerate Sayama's craziness and call him out on the stupid things he does.
- Strong Family Resemblance: She looks identical to her mother, Yukio Shinjou.
- Taking the Bullet: At the end of the sixth arc, Shinjou shields Sayama from Mikoku's knife and gets critically injured.
- Tareme Eyes: Her eyes are big and round, reflecting her sweetness and naivety.
- Took a Level in Badass: As the series progresses, Shinjou gets over her self-doubts and becomes much more competent in battle.
- Tsundere: Sweet type. Shinjou is a naturally sweet-tempered and gentle girl, but Sayama's antics and perversions bring out her violent side.
- Walking Spoiler: Knowing too much details about Shinjou gives away that "Sadame" and "Setsu" are the same Shinjou, as well as her Sex Shifter condition.
- Write What You Know: In-Universe. The story of Shinjou's novel is based on her adventures with Sayama. At the end of the series, she decides to keep dedicating herself to write whatever he does in the future.
- Write Who You Know: In-Universe. The main characters of Shinjou's novel are based off of Sayama and herself.
Kaku Izumo
Voiced by: Kissho Taniyama (Drama CD)
Taka-Akita Academy's Student Council president and Team Leviathan vanguard force along with his partner Chisato Kazami, who is also his girlfriend. An irresponsible and cheerful individual. He is the son of the current president of IAI and a goddess of 10th-Gear.
- An Arm and a Leg: He loses his left arm while protecting Kazami from the attack of Ikkou and Mitsuaki. It grows back not long afterwards.
- Badass Longcoat: He wears a longcoat as part of his UCAT uniform.
- Battle Couple: With Chisato. Together they form the Team Leviathan vanguard force.
- Beta Couple: He and Kazami play this towards Sayama and Shinjou, particularly in the first two arcs. Izumo and Kazami have been dating for two years and while they buttheads sometimes, they have a stable relationship in contrast to Sayama and Shinjou who have to get to know each other before becoming fully established as a couple.
- BFS: He wields V-Sw, an enormous Cowling Sword.
- The Big Guy: He's the largest member of Team Leviathan, in terms of size of both his body and his weapon and personality.
- Child of Two Worlds: He's the son of a man of Low-Gear and a woman of 10th-Gear.
- First-Name Basis: He and Kazami call each other by name.
- Held Back in School: He's a third-year high school student despite being twenty years old, making him a legal adult.
- Henpecked Husband: He and Kazami are not actually married yet, but she surely has him whipped already. Kazami is even labelled his "violent controlling wife".
- The Illegible: Sayama compares Izumo's handwriting to "the death throes of an earthworm suffering from a twisted intestine". Ironically, his awful calligraphy is the most effective in a 1st-Gear Concept Space.
- Language of Love: Because he lived most of his life in a 10th-Gear reservation, Izumo didn't know Japanese when he met Kazami and she had to teach him, which was how they first bonded.
- Like an Old Married Couple: He and Chisato have been dating for two years, live together in his dorm and constantly bicker like they were married already. They're basically a borderline Common Law Marriage.
- Lovable Sex Maniac: He's obsessed with breasts, particularly Kazami's, and never misses the chance to make a perverted comment or grope his girlfriend. Kazami beating him is usually what follows.
- Made of Iron: The divine protection of his mother and grandmother makes him more endurable than any human. That's why he can take Kazami's beatings on regular basis.
- Malicious Misnaming: He misspells Robert Boldman's last name as Baldman.
- Man, I Feel Like a Woman: When he and Chisato swap bodies, Kaku takes the opportunity to grope her breasts. He also says he took the liberty to do some "important research".
- Out of Focus: Izumo is the only member of Team Leviathan who never gets a character arc of his own and his prominence is considerably limited compared to his teammates. Even his girlfriend Kazami gets more character focus than him.
- Semi-Divine: He is the son of a Low-Gear human and 10th-Gear goddess, so he is a Low-Gear and 10th-Gear mixed race that has inherited divine protection from his mother.
- Student Council President: He is supposed to be this, but he hardly takes his position seriously.
- Vitriolic Best Buds: The way he and Sayama trash talk to each other is proof of how well they get along.
Chisato Kazami
Voiced by: Ai Maeda (Drama CD)
Taka-Akita Academy's Student Council treasurer and Kaku Izumo's girlfriend who lives with him in the Academy's dorms. She's part of Team Leviathan vanguard force along with her boyfriend. Originally she was an ordinary person, but two years before the story began, she became a member of the Japanese UCAT after she got involved in the Leviathan Road with 6th-Gear and 10th-Gear.
- Action Girl: She's the only female close-range fighter in Team Leviathan.
- Anger Born of Worry: After Izumo recovers from their fight against Ikkou and Mitsuaki, the first thing Kazami does is kicking him and throwing his motorcycle at him in retribution for making her worry so much and then joking about it.
- Badass and Baby: She has to fight her second battle against Ikkou while holding a baby that got trapped inside the Concept Space by accident.
- Battle Couple: With Kaku. She's his girlfriend and partner in the vanguard force.
- Beta Couple: She and Izumo function as one to contrast Sayama and Shinjou, particularly in the first two arcs. They have been together for years and act like they're married already, which makes them more stable in comparison to Sayama and Shinjou taking a while before officially becoming a couple.
- Boyish Short Hair: She has a quite boyish hairstyle, fitting her headstrong and aggressive personality.
- Cool Big Sis: She acts the role of a carefree older sister to her underclassmen.
- Does Not Know Her Own Strength: The power of 10th Gear's Concept Core gives her Super-Strength. The most frequent target of her violence is Izumo, who is tougher than a regular human thanks to descending from a goddess. As a result, Kazami fails to measure her strength when she uses it against regular people, like when she accidentally makes Shinjou bleed from the mouth after slapping her face only once.
- Fashionable Asymmetry: She wears one normal fingerless gloves and an elbow-length one in her UCAT uniform.
- Fiery Redhead: Her hair is auburn-colored, which is perfect for a hotheaded and violent girl like her.
- Florence Nightingale Effect: She first met Kaku when she found him and took him in after he was attacked by a group from 6th-Gear. Although Kaku says she wasn't the best nurse as she threw him in a wax storage room and forgot about him for half a day.
- Goggles Do Nothing: She always sports a pair of goggles on her head without practical purpose.
- Heroic BSoD: She shuts down for a short amount of time after hers and Izumo's concept weapons are severely damaged during their fight against Ikkou and Mitsuaki and Kaku loses an arm protecting her.
- Like an Old Married Couple: Although they're still dating, Kazami acts like Izumo's nagging wife most of the time. Even her own parents point out how they argue like they're an old married couple already. Since they're living together, they could be considered a Common Law Marriage in some ways.
- Only Sane Woman: Within a Team Leviathan full of eccentric individuals, she is the one of the most grounded in common sense.
- Power Gives You Wings: She uses the Concept Equipment X-Wi, which produces yellow wings of light that allow her to fly across the battlefield.
- Steven Ulysses Perhero: Kazami means "weathervane", relating to her power to bring out wings to fly. As Sayama says, "she has the power to live up to her name".
- Super-Strength: Because of the blessing of G-Sp2, Kazami has a superhuman strength. Izumo is able to withstand her blows thanks to the divine protection of his mother and grandmother from 10th-Gear.
- The Team Normal: Unlike the other members of Team Leviathan, Kazami is an ordinary girl from a perfectly normal family with no relation to the Concept War, the Gears and UCAT. This is pointed out by Kazami herself and she worries she probably doesn't fit into the group when she has no backstory related to the Leviathan Road.
- Tsundere: Harsh type. Kazami is very bold, hot-tempered and prone to comedic violence, especially when her boyfriend is being a perverted idiot. She still has her share of soft and caring moments.
Ryuuji Hiba
The grandson of Ryuutetsu Hiba, who destroyed 3rd-Gear. Ryuuji says 3rd-Gear is tainted by an impurity he must cleanse before handing the Concept Core to Team Leviathan. He wants to obtain the other half of 3rd-Gear's Concept Core because he believes it will allow Mikage's evolution into human to resume its course. He becomes Kazami's assistant in the Student Council.
- Battle Couple: He pilots Susamikado together with Mikage in battle.
- Bully Magnet: His teammates bully him all the time and the people of UCAT threaten him with weapons out of jealousy of his closeness to Mikage. The only person who is ever nice to him is Mikage.
- Cain and Abel: The Abel to Tatsumi's Cain. He once viewed her as his sister, but now she has joined the Army and has full intent to fight him as a member of UCAT.
- The Caretaker: Due to the lack of mobility of Mikage's body, Ryuuji is the one who takes care of almost everything for her, such as carrying her around, pushing her wheelchair and helping her wash her body in the bath. He also gives her speech training by reading her journal entry aloud and have her move her mouth to emulate his.
- Childhood Friend Romance: With Mikage. Ryuuji has known her since he was six years old and they were raised together by his mother. Ryuuji and Mikage obviously love each other.
- Covert Pervert: He tries to be discreet about it, but he's as much of a pervert as Sayama and Izumo. When under the effect of the interrogation device Shameful 2000, he blurts out his dirty thoughts about Mikage and the other girls in Team Leviathan.
- Early-Bird Cameo: He appears briefly in the second arc when he goes to visit his grandfather's dojo to take some pickled vegetables for his girlfriend.
- Family Theme Naming: Ryuuji Hiba, son of Ryuuichi Hiba and grandson of Ryuutetsu Hiba.
- From Roommates to Romance: Ryuuji and Mikage have lived together for ten years, ever since his father left her in the care of him and his mother. Ryuuji has always loved Mikage and she feels the same way about him.
- Martial Arts Headband: He usually wears a white headband around his head.
- Nice Guy: A very kind-hearted and polite boy.
- Red Eyes, Take Warning: Inverted. He has red eyes, but is an all-around Nice Guy.
- Robosexual: He has very obvious feelings for his automaton partner, Mikage. Although, she eventually becomes a human like him.
- Scars Are Forever: He has a scar running in a diagonal line along his forehead.
- Took a Level in Badass: In the sixth arc, Ryuuji realizes his physical abilities aren't enough to put a fight against people as strong as Tatsumi and he decides it's time for him to stop relying on Susamikado all the time. Ryuuji is then able to win representative fights against Atsuta and Hajji.
- You Killed My Father: Subverted. Tatsumi tells Ryuuji he should consider her his most hated enemy because she stabbed his father, which she thinks was the cause of his death. Ryuuji, however, can understand his father wanted to sacrifice himself to save Low-Gear and he chooses to not hold his death against Tatsumi.
Mikage Hiba
Click here to see her final evolution
An automaton who was left in the care of the Hiba family by Ryuuji's father shortly before he died ten years before the start of the series. Mikage is the youngest child of the last king of 3rd-Gear, Zeus. Before she was born, Zeus planned to use Mikage for a cloning program to increase the population of 3rd-Gear. To protect her child, Mikage's mother Rhea betrayed 3rd-Gear and fled to Low-Gear. However, Mikage was abducted by Zeus and Apollo shortly after her birth. Since Mikage's body would grow into one that could not bear children, her grandfather Cronus transferred her into the body of an automaton that would evolve into a human able to have children. However, the evolution of Mikage's body stopped five years ago for some reason. Initially, Mikage's automaton body doesn't function well; she can't walk nor speak, but she can move a little thanks to the philosopher's stone inserted in her body. Later on, Mikage's body resumes its evolution and her physical capacities improve as she gradually becomes a full human being.
- Asleep for Days: Early in the sixth arc, Mikage is left unconscious for days as she recovers from Tatsumi's attack on her and Ryuuji. She wakes up in the middle of the final arc.
- Battle Couple: She fights together with Ryuuji by copiloting Susamikado.
- Beautiful Dreamer: Ryuuji thinks Mikage's sleeping face is cute.
- Become a Real Boy: Mikage originally was a naturally-born human, but she was transferred into an automaton body shortly after her birth. Her robotic body slowly evolves into a real human being.
- Buxom Beauty Standard: After fully transforming into a human, Mikage has the biggest breasts out of the girls in Team Leviathan, to Ryuuji's great delight.
- Childhood Friend Romance: With Ryuuji. Mikage has been together with him since he was six years old and they obviously love each other.
- Cute Mute: Initially, Mikage's vocal cords are still immature, so she can't talk unless she's combined with Ryuuji in Susamikado. As her body evolves, she gains the ability to speak normally outside Susamikado.
- Emergent Human: Mikage is a special automaton programmed to slowly evolve into a human being. As her evolution progresses and Mikage learns more about the world and being human, she gains more control of her body and starts to understand emotions.
- From Roommates to Romance: Mikage has lived with Ryuuji and his mother for ten years. Ryuuji has always loved Mikage and she feels the same way about him.
- Hair Color Dissonance: After her evolution into a human being is completed, the light novel describes Mikage's new hair color as black, but it looks closer to dark blue in colored illustrations.
- Hair of Gold, Heart of Gold: Mikage has blonde hair, and an extremely pure-hearted, gentle personality.
- Happily Adopted: After Ryuuji's father left her at the Hiba residence, Mikage was raised alongside Ryuuji by his mother. She unofficially took the Hiba surname because they're the only family she has ever known.
- The Ingenue: Mikage became active until ten years ago and her life has been very sheltered while being taken care of by the Hiba family, so she's very innocent like a small child. The sexual innuendo made by almost everyone around her goes right over her head.
- Innocent Fanservice Girl: She doesn't get why it should be embarrassing for her to take baths with Ryuuji since he always helped her clean herself when she couldn't move. Once her body obtains the parts needed to have children, Mikage immediately asks Ryuuji to take a bath with her so he can see her new human body.
- Locked into Strangeness: Once her evolution into a human is completed, Mikage's blonde hair changes to black, while conserving a single blonde strand in her bangs.
- Mandatory Motherhood: The automatons of 3rd-Gear try to kidnap Mikage because she's the last surviving 3rd-Gear human along Apollo. They hope Mikage marries her own half-brother Apollo in order to preserve the 3rd-Gear royal bloodline.
- Meaningful Name: Mikage means "beautiful shadow". When Mikage was born, her mother saw the early morning scenery and she thought it warranted that name for her daughter. Since 3rd-Gear didn't have that, she gave her that name to remind Mikage that she was a child of Low-Gear.
- Mundane Utility: She mentions that she has used Susamikado to take Ryuuji's mother to the grocery store sometimes. Shinjou is surprised she has managed to not get seen by normal people.
- Odd Name Out: Mikage is the only character from 3rd-Gear that doesn't have a name related to Greek mythology. Justified, since her mother wanted her to have a Low-Gear name.
- Older Than She Looks: Mikage was born in the middle of the Concept War sixty years ago. She looks like a teenage girl because her automaton body didn't start functioning until the Great Kansai Earthquake ten years ago.
- Out of Focus: Aside from the third arc, Mikage is the member of Team Leviathan that gets the least focus right after Izumo.
- Protectorate: Ryuuji's main motive is to protect Mikage at any costs.
- Psychosomatic Superpower Outage: The real reason Mikage's evolution stopped was her own fear of becoming human and how it might affect her relationship with Ryuuji. Once she overcomes those fears, her body reassumes its evolution.
- The Quiet One: Even after becoming able to speak, she isn't the most talkative person around.
- Robot Girl: An automaton with the appearance of a young girl.
- Silent Bob: Ryuuji can communicate with her despite her not being able to talk initially. He can even have phone conversations with her because he can get an idea of what she's thinking.
- Single Woman Seeks Good Man: She has feelings for Ryuuji, who is a kind-hearted boy and always does nice things for her.
- Speech-Impeded Love Interest: Mikage's immature vocal cords don't allow her to speak clearly, so she can only communicate with Ryuuji through lip movements and her journal. He also tries to help her with it by giving her speech training.
- Sugar-and-Ice Personality: Mikage is the most inexpressive and reserved girl in Team Leviathan, but also the most loving and sweetest one.
- Synchronization: Any damage done to Susamikado gets instantly transferred to Mikage.
- Throwing Off the Disability: As her body continues to evolve into a human, Mikage gains the ability to freely move, walk and talk on her own.
- Token Robot: She's initially an automaton and joins Team Leviathan, where all the other members are humans. Subverted as she gradually transforms into a human.
- The Unintelligible: At first, Mikage can only mutter unintelligible sounds that can only be understood through her lip movements. After her vocal cords evolve, she can speak intelligible words.
Dan Harakawa
Voiced by: Hiroshi Okamoto (Drama CD)
A Japanese-American student from Sayama's class who has a reputation as a delinquent due to frequently skipping class. He has a part-time job at the Yokota Air Base and is currently living alone in an apartment due to his father dying in the Great Kansai Earthquake and his mother being hospitalized because of an illness she got when helping with said earthquake. He becomes involved in the Leviathan Road when he finds and takes in Heo Thunderson when she's running away from the 5th-Gear black mechanical dragon Black Sun. He soon decides to join the fight in order to protect Heo. He becomes Sayama's assistant in the Student Council.
- Accidental Pervert: Harakawa has a tendency to end up in all sorts of compromising situations with a naked Heo. This makes him look as big of a pervert as his male teammates, but Harakawa's case is entirely unintentional.
- Battle Couple: He pilots the Thunder Fellow while Heo synchronizes her senses with it to assist Harakawa.
- Bookworm: He loves to read books and secretly wishes to open a bookstore someday.
- But Not Too Foreign: His father was American and his mother is Japanese.
- Chekhov's Gunman: He makes short, not much relevant appearances in early arcs. It's until the fourth arc when he finally becomes involved in the story and reveals his important role.
- Cool Shades: He always wears sunglasses to show his aloof, cool character.
- Deadpan Snarker: He spends a lot of time making sarcastic remarks at the ridiculous antics of his teammates.
- The Dulcinea Effect: He decides to risk his life in order to protect a girl he has known for a couple of days.
- From Roommates to Romance: Harakawa lets Heo stay at his house when she's on the run from Black Sun. They become a couple soon afterwards and Heo moves into his house permanently.
- Full-Name Basis: He usually calls others by their full name. The only exception is when he occasionally calls Heo by her first name.
- Japanese Delinquent: He's always skipping class and drinks beer despite being underage.
- Jerk with a Heart of Gold: He may appear to be rough, moody and rude, but he's a nice and protective person.
- Master of the Mixed Message: Harakawa switches back and forth between acting like Heo's boyfriend and a protective older brother figure. This makes Heo question how serious Harakawa is about liking her.
- Minor Living Alone: He's a second-year high school student living alone at an apartment because his father is dead and his mother is hospitalized. Later, Heo moves in with him.
- Nom de Mom: He uses his mother's surname Harakawa instead of his father's surname Northwind due to his resentment towards his father.
- One Head Taller: He tops Heo's height by a full head.
- Only Sane Man: Harakawa is the only totally normal and levelheaded person in a team full of perverted weirdos and quirky fellows. He even lampshades it by stating he probably has antibodies against the disease that makes everyone around him so crazy.
- Opposites Attract: Harakawa is rude and snarky while his girlfriend Heo is meek and hypersensitive.
- She Is Not My Girlfriend: When faced by rumors that say he's living with his girlfriend, Harakawa denies his relationship with Heo, claiming she's too young for him.
- Shoo the Dog: After Tatsumi's attack on Ryuuji and Mikage early in the sixth arc, Harakawa realizes just how dangerous the Leviathan Road could be for Heo. He breaks off his partnership with her and orders her to stay in a safe place until everything is over. This greatly saddens Heo because she thinks Harakawa is abandoning her.
- Skipping School: He rarely shows up at school.
- Token Minority: He's the only dark-skinned member of Team Leviathan due to being Japanese-American.
- Tsundere: He's very gruff around Heo, but it's obvious he cares about her.
Heo Thunderson
A middle school student from America and the great-granddaughter of Richard Thunderson, the one responsible for the destruction of 5th-Gear. She came to Japan with her great-grandfather to cooperate in the Leviathan Road with 5th-Gear, but when they arrive, they are attacked by the 5th-Gear black mechanical dragon Black Sun. Richard tells Heo to run away while he stays behind to challenge Black Sun and is killed by it. During her escape, Heo passes out in front of Dan Harakawa's apartment and is taken in by him.
- A-Cup Angst: Heo gets concerned about her lack of assets when she's made to think Harakawa believes in the Buxom Beauty Standard. Taking advice from the busty Diana, Heo decides to try and massage her chest to make it grow bigger.
- Animal Motifs: She's frequently compared to a cat.
- The Baby of the Bunch: Heo is the youngest member to join Team Leviathan due to still being a middle schooler.
- Battle Couple: She assists Harakawa in battle by essentially combining with Thunder Fellow, the mechanical dragon he pilots.
- Butt-Monkey: She's a frequent target of her teammates' teasing.
- From Roommates to Romance: Soon after arriving in Japan, Heo ends up staying at Harakawa's house after he finds her during her escape from Black Sun. After they become a couple, Heo decides to move in with Harakawa permanently.
- Going Commando: When affected by Mitsuaki's fixed concept, Harakawa accidentally pulls down Heo's panties. She spends the rest of the fight without panties on.
- Gorgeous Gaijin: Heo is a blonde, blue-eyed American cute young girl. Unlike most examples, she's short and flat-chested, but that doesn't stop the series from making her get naked whenever possible.
- Hair of Gold, Heart of Gold: Young, innocent, kind-hearted and coincidentally a blonde.
- Innocent Blue Eyes: She has blue eyes, symbolizing her young age and innocence.
- Meaningful Name: Her name means "happiness" in 5th-Gear's language.
- Miss Conception: Heo thought Harakawa got her pregnant when he kissed her.
- Ms. Fanservice: Only Shinjou has more nude scenes than Heo.
- Opposites Attract: The meek and hypersensitive Heo hooks up with the rude and snarky Harakawa.
- Phenotype Stereotype: As stereotypical for American girls, Heo is a blonde with blue eyes.
- Prone to Tears: She cries way too easily.
- Raised by Grandparents: After both her parents died, she was raised by her adoptive great-grandfather.
- Reluctant Fanservice Girl: The number of times Heo cries after ending up naked in front of Harakawa are far too many to count.
- Shrouded in Myth: When she was young, Heo's mother was killed by Black Sun and everyone who saw it thought it was a demon. After that, Heo and her great-grandfather moved several times and everywhere they went, the story of Heo's mother's death would get out and she would be known as the girl saved from a demon attack. She went from being the girl protected by god to being loved by a demon and sometimes she was said to be on the run after killing the people of her old town. Heo had a very hard time because of those rumors.
- Sleeps in the Nude: She always goes to bed naked, even when Harakawa is sleeping in the same room as her. This is a problem because she sometimes forgets to put something on when she wakes up and gets exposed in front of Harakawa again.
- Survivor Guilt: When Black Sun attacked her mother and later her great-grandfather, they told Heo to run away and stayed behind to be killed by the mechanical dragon. Heo felt guilty for essentially leaving her family behind to die and only saving herself.
- Synchronization: In battle, Heo has to synchronize her senses with Thunder Fellow so she can control its limiters.
- Tareme Eyes: Her big and droopy eyes suit her role as the youngest and cutest member of Team Leviathan.
- Token Mini-Moe: She's flat-chested, short and younger than the rest of Team Leviathan.
- Tragic Keepsake: She has a philosopher's stone necklace that she got from her deceased mother.
Japanese UCAT
Kazuo Ooshiro
Voiced by: Eiji Maruyama (Drama CD)
The head of Japanese UCAT.
- Big Good: He's the head of Japanese UCAT, the secret organization in charge of handling the survivors of the destroyed Gears and save the world from letting its own negative concepts destroy it.
- Butt-Monkey: Nearly all of Ooshiro's scenes have him getting insulted, beaten and tormented in different ways by the people who work for him.
- Character Tics: He habitually gives a thumbs-up as a character quirk.
- Dirty Old Man: His hobbies include collecting erotic figures and photos of beautiful women as well as playing eroges.
- Dodge the Bullet: When a dog-possessed #8 shoots at him with a gun, Ooshiro skillfully dodges all her bullets with dance moves.
- The Friend Nobody Likes: Absolutely nobody in UCAT likes him even a tiny bit because he's nothing but a Dirty Old Man. His employees and his own son all treat him like garbage and many express their disappointment whenever they see Ooshiro hasn't been killed in battle.
- Idiot Hair: He has a long cowlick that stands prominently atop his head.
- Meaningful Name: Kazuo contains the kanji for 1. His father gave him that name because he wanted him to be #1 in everything.
- Mr. Exposition: He explains to Sayama and the reader about the other Gears, the Concept War and the Leviathan Road.
- Opaque Lenses: His eyes can't be seen because of his opaque glasses.
- Outliving One's Offspring: His son Itaru dies towards the end of the series while Ooshiro survives.
- Pointy-Haired Boss: It's very easy to forget Ooshiro is the chief of Japanese UCAT because all he ever does is play eroges and be mercilessly bullied by his own employees.
- Wacky Parent, Serious Child: He is a complete goofball, while his son Itaru is more serious and usually tries to straighten him up the hard way.
Itaru Ooshiro
Voiced by: Kazuya Nakai (Drama CD)
The son of Kazuo and the supervisor of Team Leviathan.
- Cool Shades: He wears a pair of sunglasses that make him look like a hardass.
- Final Speech: He leaves a recording of one last speech for Sf to play it for the members of UCAT in order to motivate them for their battle against the Leviathan.
- The Gadfly: He tries to get reactions out of Sf with no success.
- Incurable Cough of Death: He occasionally coughs up blood to indicate symptoms of a critical illness. He suffers from a terminal illness caused by negative concepts, which ultimately takes his life.
- Jerkass: He's not a pleasant person to be around, to say the least. It's most notable in his interactions with Sayama, his own father and Sf.
- Mr. Exposition: He gives expositions to the reader occasionally, usually through conversations with Sf about the Gears.
- No Body Left Behind: He dies at the blast caused by Leviathan's attack on Japanese UCAT's headquarters, leaving nothing of his corpse behind.
- Survivor Guilt: During the destruction of Top-Gear, Itaru got trapped inside a barrier that would send anything inside to the nothingness and the only way to escape was a mechanical dragon that only had space for one person. Ryuuichi Hiba, James Thunderson and Alberto Northwind ordered Itaru to get on the mechanical dragon while they stayed behind, which resulted in their deaths.
- Trash of the Titans: His office has books, documents, cardboard boxes, and packaging piled up all across the floor.
- Wacky Parent, Serious Child: He's way more serious and brooding than his perverted goofball of a father. It's usually Itaru's job to try and straighten him up the hard way.
- Your Days Are Numbered: Itaru has a terminal illness caused by the negative concepts he was exposed to in Top-Gear. His body reaches its limit in the final volume.
Sf
Voiced by: Yui Kano (Drama CD)
Itaru's personal maid and an automaton created by German UCAT using 3rd-Gear technology.
- Action Girl: A very formidable fighter, especially when it comes to protecting her master.
- Badass Boast:"I was created for the sake of my master. I sacrifice my steel for his bones, my chains for his flesh, my oil for his blood, and my determination for his heart. But there is one thing he has for which I have nothing to sacrifice. His tears... As I have no emotions, I have nothing to give in return for those. As such, I do not desire my master's tears. I desire only an outcome that requires no teardrops."
- The Bore: Itaru finds her extremely boring due to her emotionless nature.
- The Comically Serious: Her complete lack of emotional reaction to anything is what makes her humorous moments so funny.
- Driven to Suicide: Itaru dies and his final order to Sf is for her to live. However, she sees no purpose to keep existing if she can't serve Itaru. In the end, Sf halts all of her functions to permanently shut herself down and join her master in death.
- Emotionless Girl: As an automaton, Sf lacks emotions.
- Feel No Pain: When Sayama asks her if she feels pain when she loses an arm, Sf says she has no sense of pain. The only pain she can feel is from being unable to remain by Itaru's side.
- Germanic Efficiency: She claims that since she was created by German people, the "most excellent people in the world", her technology and combat abilities are top notch.
- Gravity Master: As standard for automatons, Sf can control gravity.
- The Gunslinger: She uses machine guns as her main weapon in combat.
- Machine Monotone: She speaks in monotone due to being a Robot Girl with no emotions. It's Played for Laughs in one occasion where Itaru handed her a pornographic manga as a prank and she read it out loud, including the texts full of shouting and sound effects, with a robotic voice.
- My Name Is Inigo Montoya:"My name is Sein Frau, 'the woman who should exist'. I am a nonhuman who was born from the desire to 'exist'. Now, come and bring the reason for your birth with you. If that reason is weaker than mine, you will not even be able to 'exist'."
- Mystical White Hair: An automaton with silver hair, which hints at her artificial origins.
- Ninja Maid: She was created to be Itaru's maid and was equipped with top combat skills to protect her master.
- Only Known by Initials: Sf, which is a shortened form of her full name "Sein Frau".
- Rei Ayanami Expy: A Robot Girl with short silver hair who lacks emotions and serves as the loyal servant of her master.
- Robot Girl: She's an automaton with the apperance of a young woman.
- Robot Maid: An automaton whose main function is to serve as Itaru's personal maid.
- Sarcasm-Blind: Every time Itaru tries to insult or mock her, his sarcasm goes right over Sf's head and this annoys him to no end.
- Sugar-and-Ice Personality: She might repeatedly proclaim to be a machine with no emotions, but her devotion to Itaru presents a very tender side to her.
- Trouser Space: She keeps weapons under her skirt using gravity control. She can even take out a Gatling gun from down there."How did you fit something so large under your skirt!?"
- Undying Loyalty: Extremely loyal and devoted to her master.
Reel Ooki
Sayama's homeroom teacher and English teacher, and Takaakita Academy's Student Council's adviser. Beneath that, Ooki is a 10th-Gear tree spirit who forms part of Team Leviathan as the one who handles the controllers for Concept Spaces.
- Cloudcuckoolander: Ooki is very weird and seems live in her own world.
- Cute Clumsy Girl: Extremely clumsy and careless. She's always late for class, often forgets her textbook, gets off the train at the wrong station, and cannot read what she herself wrote on the board.
- The Ditz: Very ditzy, absentminded and forgetful. Sayama likes to call her out on her foolishness.
- Genki Girl: She has a very cheerful and energetic personality.
- Hide Your Otherness: She keeps her Pointy Ears hidden when she works as a teacher.
- Idiot Hair: She has a cowlick that sticks straight up from her head. It highlights her ditzy and childish personality.
- Nature Spirit: She is a tree spirit from 10th-Gear.
- Nice Girl: She's nice and friendly to everyone, even the enemies of UCAT such as the Army.
- Not a Morning Person: She always has trouble getting up in the morning and she's usually late for her class because of it.
- Plucky Comic Relief: Every time she appears is mainly to bring comic relief to the scene.
- Pointy Ears: She has long elf-like ears to show her nature as a tree spirit.
- Secret Secret-Keeper: She admits she figured out the Shinjou twins were one and the same from the beginning, but she kept it to herself.
- Sensei-chan: She's young, rather inexperienced as a teacher, cute and very childish. Her own students usually treat her like a child.
- Womanchild: She acts way more immature than her students. One time, she actually starts crying like a little kid when her forehead slams into a table.
Sei Chao
The medical chief of Japanese UCAT. In the past, she belonged to Chinese UCAT and was the Eight Great Dragon Kings member in charge of 7th-Gear.
- Anime Chinese Girl: She's a (seemingly) young Chinese girl who wears a qipao and has her hair in a pair of odango.
- A Good Way to Die: She has one final conversation with the Four Dragon Brothers. They express they never resented her for creating them and had plenty of fun living with her in Low-Gear. Happy to hear that, Chao thanks them and dies satisfied with her life.
- Go Out with a Smile: After Diana brings the Four Dragon Brothers' Concept Cores to her, Chao passes on with a satisfied smile on her face.
- Labcoat of Science and Medicine: She's The Medic of Japanese UCAT and fittingly, she always wears a labcoat.
- Motherly Scientist: Not originally, as she had created the Four Dragon Brothers just to experiment with 7th-Gear's technology. Over the decades, however, she at some point came to view them as her sons and began lamenting the possibility that she had only brought them into existence only for them to disappear eventually.
- Older Than She Looks: Chao looks like a young girl, but she's actually an old woman who has used a philosopher's stone to remain young.
- One Last Smoke. Played With. She tries to have one last cigarette, but she dies before she can light it up. Diana then places the cigarette in the already dead Chao's mouth.
- Outliving One's Offspring: Her "sons" are all defeated by Team Leviathan and turn back into Concept Cores. Having reached the end of her lifespan, Chao joins them in death.
- Smoking Is Cool: She's almost always smoking cigarettes to show off her cool-headed and smart character. It also showcases how she's actually an old woman despite looking like a preteen.
- Supernaturally Young Parent: As the scientist that created them with 7th-Gear's science, Chao is the "mother" of the Four Dragon Brothers. Because of the power of a philosopher's stone, Chao has the appearance of a young girl while the brothers look like old men as a result of their boredom accelerating their aging.
- Token Mini-Moe: She's the only staff member of UCAT who looks like a little girl, although she's really one of the oldest members.
- Your Days Are Numbered: While she did keep her body from aging and extended her lifespan with a philosopher's stone, Chao spent a lot of time inside a space of distorted time in 7th-Gear as she created the Four Dragon Brothers. Once the brothers are about to disappear, Chao knows she also won't last much longer.
The Four Dragon Brothers
Ikkou, Nijun, Mitsuaki and Yonkichi are a group of brothers that usually hang around Doctor Chao. The truth is they are the vessels of 7th-Gear's Concept Core.
- Anthropomorphic Personification: They're 7th-Gear's Concept Core split into four and given human forms.
- Artificial Family Member: Although she had originally created them For Science!, Chao grew to think of the brothers as her own sons over the years.
- Artificial Human: They were created by Chao, using 7th-Gear's techniques for bodily modifications.
- Attack Reflector: Yonkichi's fixed concept allows him to "reverse the world", causing any attack aimed at him to be redirected to his opponent by swapping places with him.
- Blood Knight: There's nothing they enjoy more than a good fight.
- Cannot Tell a Lie: Nijun's fixed concept makes it impossible for himself and his opponent to lie or deceive in any way.
- Desperately Looking for a Purpose in Life: They were created so they could eventually decide whether Low-Gear deserved 7th-Gear's Concept Core and then disappear. Besides seeking to amuse themselves, they challenge Team Leviathan so they can answer what was the purpose of their birth besides disappearing.
- Dumb Muscle: Yonkichi was made the strongest physical fighter of the brothers, but also the dumbest.
- It Amused Me: Before they reach the end of their lifespan, they challenge Team Leviathan to have as much fun as possible before they disappear.
- Numerical Theme Naming: Each of their names includes the character that indicates the numerical order in which they were created.
- Rapid Aging: Their aging process speeds up depending on how bored they feel.
- Religious and Mythological Theme Naming: They're named after the dragons that became the four great rivers of China in Chinese Mythology.
- Support Party Member: Mitsuaki isn't as capable in battle as his brothers, but his fixed concept leaves their opponents unable to comprehend anything about their surroundings, making it much easier for his brothers to defeat them. Mitsuaki himself notes that he was given a support role so there's a balance among the brothers.
- Verbal Tic: Yonkichi has a habit to end his sentences with silly words, such as puru, ges and gelge.
- "Well Done, Son" Guy: Unlike his older brothers who are more interested in having fun and testing their skills, what Yonkichi wants the most is to make their creator Doctor Chao proud. He thinks surpassing the descendants of her old companions is his way to achieve that. Before he's killed by Shinjou and Susamikado, he realizes he helped his opponents become stronger and he believes that will make Chao happy.
- Your Days Are Numbered: As they have lost interested in life on Low-Gear, they're aging rapidly and their lifespans are reaching their end.
Sibyl
The one in charge of communications and maintaining equipment on site for Team Leviathan. She has a connection to 3rd-Gear.
- Artificial Family Member: She was created by Cronus as a prototype model for Mikage, so she thinks of Mikage as something like her younger sister or her daughter.
- Artificial Human: Cronus created her as the prototype for the automaton model that would develop into a human girl. While she's mostly human, Sibyl's evolution is not as advanced as Mikage so she retains some mechanical features.
- Gravity Master: Since she's an automaton, she has control over gravity. She often uses it to move Gods of War.
- Hair of Gold, Heart of Gold: A woman with long blonde hair who is sweet and kind-hearted.
- Innocent Blue Eyes: Her eyes are blue which reflects her kind and pure-hearted nature.
- Nice Girl: Polite, sweet-natured and kind.
- Religious and Mythological Theme Naming: In Classical Mythology, the sibyls were oracles who gave prophecies influenced by divine inspiration.
- Robotic Reveal: Her clothes get torn off when protecting Mikage from an attack. Mikage sees Sibyl's body has lines similar to her own and Sibyl reveals she and Mikage have access to each other's shared memory. This makes Mikage realize Sibyl is an automaton of the same model as her.
- Tareme Eyes: She has large, droopy fitting her sweet and cute character.
# 8
An automaton created from 3rd-Gear technology who originally resided in the Kanda laboratory. After the negotiations with 3rd-Gear, she's transferred to UCAT and assigned as Kazuo Ooshiro's caretaker.
- The Caretaker: She's assigned to look after Ooshiro as his personal assistant, not that she's enthusiastic about it or does her job very well.
- The Comically Serious: She's mostly funny during comical scenes because of her emotionless reactions.
- Deadpan Snarker: She often makes sarcastic quips at the idiocy of those in UCAT, particularly Ooshiro.
- Emotionless Girl: As standard with automatons, #8 has no emotions.
- Guns Akimbo: She usually fights with a gun in both hands.
- The Gunslinger: She specializes in fighting with guns.
- Nothing Up My Sleeve: She pulls her guns out of her sleeves.
- Servile Snarker: After being made Ooshiro's assistant, she never misses the chance to mock him and throw sniping comments at him.
- Tears from a Stone: She cries a single tear when Ooshiro humiliates her by forcing her to lick his hand when a dog is controlling her body. When confronted about it, she claims an automaton has no emotions so she isn't affected by it, but her reactions say otherwise.
- You Are Number 6: Her only name is #8.
German UCAT
Diana Zonburg
A member of German UCAT and Siegfried's niece who was sent to Japan as European UCAT's inspector for Team Leviathan. She is also Germany's greatest witch and is the only surviving member of the Five Great Peaks. She was the teacher of Heo Thunderson and is the wife of Colonel Odor from American UCAT.
- Action Girl: Shortly after her introduction, she gives Brunhild a hard time in a duel in which Diana wasn't serious in the first place and then she kicks Izumo's and Sayama's asses in training. She's not known as Germany’s greatest witch for nothing.
- Battle Couple: With Odor. Diana is the strongest witch from Germany and her husband Odor is a Colonel Badass.
- Hot Witch: Known as Germany's greatest witch and she makes sure to look young and attractive for her age.
- Mystical White Hair: A witch with silver hair.
- Older Than She Looks: Thanks to a philosopher's stone, she looks like she's in her twenties when she's actually much older.
- Red Baron: She was once known as the "Mother Cat".
- Sitcom Arch-Nemesis: With Brunhild. Whenever the two witches are together, they're fighting or arguing about which of them is stronger.
- Vain Sorceress: She used a philosopher's stone to make herself look young.
American UCAT
Colonel Odor
The inspector of American UCAT. After Richard Thunderson's death, he comes to Japan to protect Heo Thunderson and demand Japanese UCAT to pass the rights of the Leviathan Road to them. He is the husband of Diana Zonburg.
- Badass Fingersnap: His main attack is a fingersnap that can crush his opponents to the ground.
- Battle Couple: With Diana. Odor is a Colonel Badass and his wife Diana is the strongest witch from Germany.
- Big Ol' Eyebrows: He has very thick eyebrows.
- Colonel Badass: He's a colonel from American UCAT and quite the badass.
- Embarrassing Nickname: He says that in his youth, he was something no one wanted around and to be avoided to everyone around him. That's why he was given the nickname Odor.
- Long-Lost Relative: He's Richard Davis, Heo's long-lost great-uncle.
- Only Known by Their Nickname: "Odor" is a nickname given to him by the people who abused him in his youth. His real name is Richard Davis.
- Scars Are Forever: His entire right arm is covered in countless overlapping scars and swellings. He says he got them in his childhood by people who treated him like a pest.
- Significant Name Overlap: His real name is Richard Davis. His father, James Davis, named him after his friend, Richard Thunderson.
- Sympathetic Inspector Antagonist: He comes to try and take the rights of the Leviathan Road from Japanese UCAT, starting a small war between their factions. While his methods are very forceful and extreme, it's hard to not think he's kind of right about Japanese UCAT being incompetent and unfit for a job that has the fate of the entire world at risk when they couldn't even protect a single important figure like Richard Thunderson. Having someone like Sayama in charge of the negotiations that will decide the fate of the world also doesn't seem a reliable idea...
- Two First Names: His real full name is Richard Davis. "Davis" can be both a given name and a surname.
- Verbal Tic: He has a habit of repeating the first word of his sentences twice.
1st-Gear and Related Characters
Siegfried Zonburg
Voiced by: Banjo Ginga (Drama CD)
The librarian of Kinugasa Library at Takaakita Academy. He makes investigation concerning the Concept War on UCAT's behalf. During the Concept War, he was responsible for the destruction of 1st-Gear.
- The Atoner: He says he wishes to atone for his past crimes against 1st-Gear.
- Badass Longcoat: He wears a black longcoat in battle.
- Cool Old Guy: His age doesn't stop him from joining the battle against the City faction.
- Heartbroken Badass: The death of Princess Gutrune still fills him with pain and guilt.
- I Let Gwen Stacy Die: Princess Gutrune was mortally wounded protecting him from a berserk Fafnir. This is a source of sorrow and regret for Siegfried to this day.
- Parental Substitute: He was something of a father figure to Brunhild when she was younger.
- Silent Scapegoat: He willingly took all the blame for the destruction of 1st-Gear and let the survivors hate him because he believed it was for the best that they hated an outsider instead of letting them know their king was the real responsible for the destruction of their world.
- Take a Third Option: Shortly before the battle between UCAT and 1st-Gear's City faction, Brunhild asks Siegfried to take care of her pet bird to see if he chooses to stay to take care of the bird or to abandon the bird to join the battle. Siegfried goes to the battle anyway, but he takes the bird with him.
Brunhild Schild
Voiced by: Machiko Toyoshima (Drama CD)
A third-year student and the head of the general art club at Takaakita Academy. In reality, she is a long-lived witch from the City faction of 1st-Gear who was assigned to an undercover mission to monitor Siegfried. She has a past with Siegfried.
- A-Cup Angst: It's not something that usually bothers her, but she does get annoyed when Kazami makes fun of her flat chest and is jealous of Ooki's voluptuous figure.
- Action Girl: She's one of the strongest enemies in the City faction. Even without Requiem Sense, she's a very competent magic user.
- All Witches Have Cats: She has a black cat Familiar.
- Broken Bird: The destruction of 1st-Gear and the apparent betrayal of Siegfried toward her and Gutrune has left her bitter.
- Compulsory School Age: Despite her actual age, her teenage appearance allows her to easily pass off as a highschool girl. She keeps going to school even after the City faction is defeated and she doesn't need to monitor Siegfried anymore.
- Cute Witch: A cute young-looking witch, complete with a cat familiar and a Flying Broomstick.
- Do Not Call Me "Paul": She won't let anyone but Hagen and Siegfried call her by her original name Nein.
- Et Tu, Brute?: She was deeply hurt by the belief that Siegfried betrayed her and Princess Gutrune by destroying their Gear. When she understands that wasn't what really happened, she makes peace with Siegfried.
- Friend to All Living Things: She has a soft spot for animals, especially birds. She adopts a little bird that quickly becomes very attached to her.
- Girlish Pigtails: She has her long hair tied into two twin tails.
- Hair Color Dissonance: Her hair is described as platinum blonde or gray in the novel, but it looks closer to pale green in colored illustrations.
- Heel–Face Turn: She starts out as an enemy, being a member of the radical City faction of 1st-Gear. After the City faction is defeated, she becomes an ally of UCAT and helps the heroes several times.
- Long-Lived: She is part of a long-lived race from 1st-Gear.
- Necromancer: She can summon the souls of the dead stored in the scythe Requiem Sense and use them against her opponents in battle.
- Older Than She Looks: While she looks like a teenage girl, Brunhild was alive during the Concept War sixty years ago.
- Parental Abandonment: Her parents died during the Concept War.
- Proper Tights with a Skirt: She wears black tights with her school uniform.
- Robe and Wizard Hat: She occasionally wears a robe and a three-cornered hat.
- Sinister Scythe: Her main weapon is Requiem Sense, a giant scythe that stores the souls it hears and is essentially the underworld of 1st-Gear itself.
- The Stoic: She usually keeps an expressionless face, but there are moments her emotions shine through.
- Sugar-and-Ice Personality: She appears to be stoic, cold-hearted and stern, but there are times she shows a softer and sensitive side.
- Tears of Joy: She's moved to tears when Siegfried saves her from the Grim Reaper she created with Requiem Sense and she realizes he didn't abandon the bird she asked him to take care of.
2nd-Gear and Related Characters
Akio Kashima
A member of the Japanese UCAT's development department who is a descendant of the family of best swordsmiths of 2nd-Gear. He has been chosen as the representative of 2nd-Gear in the Leviathan Road, but he feels troubled about accepting the position since an incident eight years prior to the series made him reluctant to accept his relation to 2nd-Gear. He is happily married to a woman named Natsu and they had a daughter recently, however hiding the truth of 2nd-Gear, UCAT and an unfortunate accident he caused from his wife gives him much conflict.
- Afraid of Their Own Strength: He sealed his power to create swords after he caused a landslide accident from testing one of his swords. Since then, he has been too afraid that his power might hurt people again.
- The Atoner: He wants to make his wife and daughter happy to atone for causing the accident that nearly killed Natsu and made her lose two fingers.
- The Blacksmith: Bearing the name of the sword god of Japanese mythology, Kashima can create very powerful swords. However, he quit swordsmithing after the accident he caused eight years ago.
- Child of Two Worlds: He's a descendant of 2nd-Gear, but he was born and raised on Low-Gear. His struggle to accept himself as part of both worlds is one of the main points of his character arc.
- Doting Parent: He's constantly watching pictures and videos of his baby daughter Harumi and showing them to people.
- Happily Married: To Natsu, who he loves deeply. However, his guilt over the truths he must hide from her, especially the one of the accident make things difficult for their marriage.
- Labcoat of Science and Medicine: He wears a labcoat to signify his job as an engineer of UCAT's development department.
- My Greatest Failure: The landslide accident he caused when he was testing one of his swords still haunts him. Especially since his wife was badly injured in the accident.
Natsu Kashima
Akio Kashima's devoted wife. An ordinary Low-Gear human, she doesn't know anything about his real job at UCAT, but she acts as supportive of her husband as she can. She hates rain because it reminds her of an accident in which she lost two fingers of her left hand.
- Fingore: She lost two fingers of her left hand in an accident years before the start of the series.
- Good Parents: She's a very loving mother to her newborn daughter Harumi.
- Happily Married: She loves her husband very much and tries to support him in every way she can, even though she doesn't know the truth behind his job and other things.
- Hidden Depths: While she seems like the perfect wife, Natsu has issues of her own. She admits to Akio she keeps secrets from him and lies often, so he shouldn't feel guilty over lying to her all the time.
- Housewife: She devotes herself to take care of her family and their home.
- Hyper-Awareness: According to Kashima, Natsu can identify people just by their footsteps.
- Locked Out of the Loop: She doesn't know the truth of her husband's job at UCAT, his relation to 2nd-Gear or the fact that he was the one who caused the landslide accident in which she nearly died.
- Tragic Dropout: She dropped out of college after being traumatized by the accident in which she almost died.
- Trauma Button: Rain reminds her of the accident in which she nearly died.
Yukihito Atsuta
Another descendant of 2nd-Gear and a close friend of Kashima. He was classmates with Ryouko Tamiya back in highschool and he has had an unrequited crush on her for years.
- Blood Knight: He loves fighting and is always eager to pick a fight.
- Delinquent Hair: He has dyed blond hair.
- Dynamic Entry: During the Army's attack on UCAT, Atsuta appears singing one of his enka songs and makes his entrance like a rock star would.
- Hopeless Suitor: To Ryouko Tamiya. He has loved her since they were in highschool, but she's completely oblivious to his feelings and Asagi Sayama was the only man she ever wanted.
- Jerk with a Heart of Gold: He may be rude and violent, but he's a good friend to Kashima and he also cares a lot about his highschool crush Ryouko.
Shizuru Tsukuyomi
The director of the Japanese UCAT's development department and bearer of the name of the imperial family of 2nd-Gear.
- Lunacy: As the bearer of the name Tsukuyomi, she has the power to control moonlight. In combat, she can throw hundreds of arrows of moonlight at her opponents.
- Never Mess with Granny: She can put a good fight for someone of her age.
3rd-Gear and Related Characters
Miyako Tsukuyomi
The rebellious daughter of the director of the development department Shizuru Tsukuyomi. Although she's a pure-blooded 2nd-Gear descendant, Miyako has no knowledge of her mother's real job at UCAT or the other Gears. After being rejected at a job interview, she gets caught in the middle of a battle between Typhon and Susamikado and she gets abducted by Typhon. After being taken "hostage", she is welcomed like a princess by the automaton maids at the mansion of the 3rd-Gear base. She soon takes an interest in their master Apollo.
- Addiction Displacement: After becoming pregnant with Apollo's child, she quits smoking. From then on, she switches to chocolate and gum cigarettes.
- Aggressive Submissive: She is tough and assertive most of the time, but when she has sex with Apollo she becomes very shy and flustered.
- Birds of a Feather: She becomes interested in Apollo as she sees herself reflected in him, both in terms of their similar situations and having lost their fathers.
- Common Law Marriage: She and Apollo haven't gone through a proper marriage ceremony, but they conceive a child together and call themselves husband and wife. After the third arc, everyone acknowledges Miyako as the queen of 3rd-Gear through her unofficial marriage to Apollo.
- Former Teen Rebel: She was a delinquent in her teenage years. She has mostly reformed, but she still has a rebellious streak in her.
- Hair Color Dissonance: Her hair looks brown in illustrations, but it's described as black in the novel.
- I Will Wait for You: After Apollo is left comatose while his body recomposition takes time to stabilize, Miyako is told he will return "eventually". Miyako knows it could take thousands of years and she will probably never see him again, but she still decides to always be waiting for his return. He does come back to her in the middle of the Final Battle.
- Labcoat of Science and Medicine: She gets a part-time job at UCAT's development department, which includes her needing to wear a labcoat.
- Law of Inverse Fertility: She wasn't expecting to get pregnant from having sex with Apollo only one time, especially when it was Their First Time.
- Locked Out of the Loop: Her mother hasn't told her anything about her real job, the other Gears or her own 2nd-Gear blood. Miyako only gets to know about the Gears and the Concept War after she's abducted by Typhon.
- A Match Made in Stockholm: Typhon kidnaps her and brings her to the 3rd-Gear base. While she's being held captive, Miyako befriends the Robot Maids and falls in love with Apollo. She even refuses to leave when Apollo gives her the chance and has sex with him shortly afterwards, becoming pregnant with his child.
- Mayfly–December Romance: With Apollo. He has likely lived for thousands of years while she's a regular human of college age.
- Meaningful Name: Miyako means "capital city". Her father had given her that name so that a great amount of people would gather around her.
- A Mother to Her Men: Once she takes leadership over 3rd-Gear's automatons, Miyako shows to care about them and treats all them as if they were people instead of machines.
- Rebellious Spirit: She always feels the urge to do the opposite she's told to do.
- Tsundere: She calls Apollo an idiot and treats him harshly, but she can't deny her attraction to him. She is even tsundere in bed.
Apollo
The last living 3rd-Gear human, son of Zeus and current king of 3rd-Gear.
- Back for the Finale: He finally wakes up and reunites with Miyako in the middle of the Final Battle of the last volume.
- Birds of a Feather: With Miyako. They fall in love because they sympathize with each other over being stuck in similar situations with their families, mainly the loss of their fathers.
- Came Back Wrong: Apollo was originally killed by Susamikado during the Concept War. In order to revive him, Artemis overwrote his death with her life, but the split and re-composition were imperfect so Apollo ended up synchronized with Typhon which is now controlled by Artemis' soul.
- Common Law Marriage: He and Miyako aren't legally married (and they probably can't anyway since Apollo isn't even a human of her world). That doesn't stop them from calling themselves husband and wife and conceiving a child together.
- Convenient Coma: During the final battle against 3rd-Gear, Artemis recomposes Apollo using the high output of the moment in which the Concept Cores in Typhon and Kevranos are joined together. However, it could take quite some time even several thousand years for the recomposition to stabilize and until then Apollo will be in a comatose state. Meanwhile, Miyako is left behind pregnant with his child, hoping to see the day Apollo wakes up.
- Curtains Match the Window: Yellow hair and eyes.
- Hair of Gold, Heart of Gold: He is described as a pacifist and he acts like a kind and princely young man.
- Last of His Kind: The last living human man of 3rd-Gear.
- Long-Haired Pretty Boy: He has long blonde hair that contributes to his princely looks.
- Long-Lived: He is part of a race that could live for thousands of years.
- Mayfly–December Romance: With Miyako. He has likely lived for thousands of years while she's a regular human of college age.
- Princely Young Man: The Prince Charming type. He's the member of a royal family who lives in a Big Fancy House filled with Robot Maids.
- Really 700 Years Old: He looks like a young man, but he has lived for at least a couple of millenia.
- Really Gets Around: Apollo had children with many women to try and increase his world's population because he was one of the few 3rd-Gear humans with the ability to reproduce. However, he later explains he never actually did the act with any of them because in 3rd-Gear everything was extracted and done outside the body. Therefore, Miyako is the only woman he has slept with.
- Reluctant Warrior: Despite being a pacifist, during the Concept War he was forced by his father to fight.
- Supernatural Gold Eyes: His yellow eyes are fitting of someone with the name of the Greek sun god and a member of a Long Lived Race.
- Synchronization: Since Apollo's re-composition was imperfect after Artemis overwrote his death, Apollo is synchronized with Typhon. Therefore, any damage Typhon receives is transferred to Apollo and vice versa.
- Uptown Guy: Apollo is the prince of another world and his common law wife Miyako is a middle-class girl.
- Wacky Marriage Proposal: He simply bows and asks Miyako to marry him before even properly introducing himself.
- What Beautiful Eyes!: Miyako finds herself drawn to Apollo's eyes because of their color and their look reminding her of herself.
The Army
Hajji
The leader of the Army and former general of 9th-Gear. He acts as an information broker for other Gears while working on his own mysterious plans.
- Affably Evil: For the leader of a shady organization that is moving everything behind the scenes, Hajji is a very polite and accurate fellow.
- Big Bad: He's the leader of UCAT's main enemy the Army and the main antagonist of the series.
- Dark and Troubled Past: He was originally the general of 9th-Gear and was supposed to protect its king who his sister was engaged to. At a battle in Low-Gear, the king was badly injured and when Hajji returned to 9th-Gear, his sister was used as the core for the mechanical dragon Zahhak. The king took the identity of the Low-Gear man who saved him, Abram Mesam. He then betrayed their world by blinding Hajji in one eye and destroying Zahhak and 9th-Gear with it. Afterwards, Hajji was taken in by Top-Gear's UCAT and was promised they would create a place for all the destroyed Gears' survivors. The destruction of Top-Gear at hands of Low-Gear's UCAT crushed that hope and cemented Hajji's hatred for the lowest Gear.
- Disc-One Final Boss: He's the leader of the Army and the most prominent major antagonist throughout most of the series. In the final volumes, Hajji is defeated by Sayama with the help of Shinjou and others and gets captured by UCAT. From that point on, the story starts building up Mikoku as the new Big Bad.
- Et Tu, Brute?: His king and best friend Sarv betrayed him along with all of 9th-Gear by joining Low-Gear's side and destroying Zahhak, the mechanical dragon made from Hajji's sister and which housed 9th-Gear's Concept Core.
- Even Evil Has Loved Ones: As shady as he can be, he does seem to genuinely care about his adoptive daughters.
- Eyepatch of Power: He wears an eyepatch over his left eye and he's an experienced military leader.
- Freudian Excuse: He desires to destroy Low-Gear because the king of his world, Sarv, betrayed 9th-Gear for Low-Gear and destroyed the mechanical dragon which had been made of Hajji's sister along with 9th-Gear's Concept Core. Further, he views Low-Gear as evil for having apparently destroyed the highest world, Top-Gear.
- Heel Realization: With the discovery that he was completely wrong about Top-Gear's creation and destruction, Hajji is forced to admit he was nothing but a villain using his unconfirmed theories of Top-Gear to take out his anger on Low-Gear.
- Hidden Agenda Villain: For a good part of the series, we have no idea what he and his Army are up to and what are their motivations.
- Knowledge Broker: He acts as an information broker who can gather weapons and accurate information.
- My Greatest Failure: He had promised his sister to bring King Sarv back to her safely and accomplish peace, but Sarv was gravely injured in their journey to Low-Gear and for his failure, the politicians of 9th Gear used Hajji's sister as the core of the mechanical dragon Zahhak.
- Power Limiter: His eyepatch acts as one for the Concept Weapon located in his left eye.
- Redemption Equals Death: After learning the real truth of the creation of the Gears, Hajji realizes the wrong of his ways. At the end, he sacrifices himself in the final battle by pulling a Suicide Attack against the Leviathan's automatons in order to protect Mikoku and Shinjou. In his final thoughts, he admits Low-Gear is a wonderful world after all.
- Taking the Bullet: He gets mortally wounded by shielding Mikoku and Shinjou from the blades of the Leviathan's automatons.
- Unreliable Expositor: About everything he reveals about Top-Gear aside from it being the positive counterpart of Low-Gear turns out to be entirely wrong assumptions drawn from misinformation and his hatred of Low-Gear. For example, he claimed Top-Gear was the original world that created all the others when the creation of the Gears was a much more complicated one that involved a Stable Time Loop.
- Well-Intentioned Extremist: He plans to destroy positive Concepts in hopes that will also destroy their opposite negative Concepts before they destroy everything. He thinks this is the only way to stop the negative Concepts because he doesn't believe UCAT's plan to release the positive Concept Cores will be able to suppress Low-Gear's negativity since Top-Gear was destroyed by the activation of negative Concepts despite their world being made of positive Concepts.
Mikoku Toda
Hajji's elder "daughter".
- Accidental Murder: At the climax of her representative battle with Sayama, Mikoku throws the Totsuka sword in the air with the intention of being stabbed by it and dying because of its Concept of names. However, Shino shields Mikoku from the sword with her own body and gets stabbed instead. Shino then bleeds to death while Mikoku can only watch.
- Action Girl: She's one of the main fighters of the Army.
- Aloof Big Sister: She keeps her adopted sister Shino at arm's length even though Mikoku loves her more than anything. Since Mikoku wants Shino to leave the Army for her safety, she distances herself from Shino believing it will make their separation less painful for both of them, but the only thing she accomplishes is making Shino think her sister doesn't care about her.
- Aloof Dark-Haired Girl: She's tall, attractive and has a reserved and composed personality.
- Anti-Villain: While she's part of the Army, Mikoku is not malevolent and the thing she cares about the most is to protect her adopted family and allies with her wish for revenge towards Low-Gear not being as prominent as others in the Army. In the final arc, she becomes the Woobie variety because she's trying to destroy the world out of grief and despair over her Accidental Murder of her adopted sister.
- Big Sister Instinct: One of her main motives is to protect her adopted younger sister Shino. She doesn't like to let Shino get involved in missions of the Army because she doesn't want to put her in danger. It's also deconstructed when we see the terrible effects failing to protect her sister has in Mikoku's emotional state.
- Broken Bird: Shino's death reduces Mikoku to an emotional wreck solely focused on taking out her grief and anger on the world.
- Byronic Hero: Mikoku shows many qualities of this despite technically being a villain. She's an attractive, brooding, isolated, self-critical and emotionally troubled individual driven by her intense emotions and damaged by her own self-destructive behavior.
- Can't Catch Up: No matter how much she trains in swordsmanship and how much her body can regenerate from wounds, Mikoku can't reach the level of others like Hajji, Tatsumi and Sayama. She finds it particularly frustrating in the last case because Sayama is supposed to be her "fake" and she should be naturally better than him.
- Cradle of Loneliness: After Shino dies, Mikoku is constantly clinging on to her lifeless corpse.
- Despair Event Horizon: Shino's death pushes her over the edge.
- Dragon Ascendant: She acts as The Dragon to Hajji for the majority of the series. From the sixth arc onwards, Mikoku takes over Hajji's position as leader and representative of Top-Gear's survivors. The final arc is about stopping Mikoku after she becomes a Woobie, Destroyer of Worlds.
- Evil Counterpart: To Sayama. It helps they are literal opposite-sex counterparts from different worlds and their own respective Gears' representatives.
- Foil: To Sayama. They're both The Stoic members of their factions, suppress their emotions because of their pasts and the two have a Morality Pet that means the world to them (Shinjou for Sayama, Shino for Mikoku). However, Sayama is arrogant, overconfident and convinced he's meant to be the most important person in the world, while Mikoku is humble, doubts herself all the time and yearns for a simple life. Also, Mikoku insists on pushing away Shino despite how much she cares about her in contrast to Sayama trying to keep Shinjou close to him at all times. This is taken further in the final volumes; Mikoku is revealed to be the female counterpart of Sayama from Top-Gear and becomes his direct adversary as the representative of Top-Gear. Their final conflict is essentially about Mikoku being obsessed with what she lost in the past in direct opposition to Sayama who only looks ahead.
- Forgotten Friend, New Foe: She claims to have known Shinjou before she lost her memory and they were close in some way, but now they are enemies as members of the Army and UCAT respectively. Mikoku really doesn't want Shinjou to be her enemy, though.
- From a Single Cell: Her Healing Factor eventually evolves into this. Even if Mikoku's body is completely destroyed, her philosopher's stone will rebuild itself upon its destruction and rapidly regenerate her body.
- Good Thing You Can Heal: Thanks to the philosopher's stone in her body, Mikoku can survive to being split in half and having most of her body destroyed.
- Healing Factor: Her parents embedded a philosopher's stone in her chest which gives her a potent regeneration ability. Although, others point out the regeneration is slow and if the philosopher's stone is destroyed, Mikoku can effectively be killed. Those problems are solved after the philosopher's stone evolves upon being destroyed.
- I Reject Your Reality: After Shino dies, Mikoku refuses to accept a world in which her adopted sister is dead. Using the power of Noah, Mikoku attempts to destroy the current reality and recreate it into one where Shino can be alive again.
- Interrupted Suicide: During her decisive confrontation with Sayama as representatives of their Gears, Mikoku attempts to take her own life under the belief all conflict will end if Top-Gear loses its leader. Everything goes wrong because she's stopped by Shino who gets stabbed by Totsuka instead and dies.
- Jumping Off the Slippery Slope: She starts out as possibly the most Anti-Villain member of the Army and then by the final volume, Mikoku is attempting to destroy everything and everyone, including herself, now that she lost the person most important to her.
- Karma Houdini: Mikoku takes control over Noah, attempts to destroy and recreate the entire world and uses the army inside Noah to try and eliminate all who oppose her. Sayama, however, declares Mikoku shall receive no retribution for her actions since he believes living on without Shino and carrying what she did in her conscience is punishment enough. Instead, he wants everyone to give Mikoku a second chance and help her live on.
- The McCoy: Mikoku takes up this role to embody the emotion that opposes Sayama's reason. Mikoku only acts on her feelings of sorrow and anger at everything that is gone (particularly Shino) and refuses to look into the future to instead demand to be given back what she lost.
- Meaningful Name: Mikoku means "to carve into life".
- Mirror Character: She and Sayama are quite similar in several ways. After all, they're technically the same person with the sex reversed. In their decisive fight at the end of the sixth arc, both even admit they're the same.
- Mirror Self: She's Sayama's female counterpart from Top-Gear.
- Necromantic: Driven mad by Shino's death, Mikoku plans to have Noah create a Concept that denies death and remake the world into one where Shino and everyone else who has died can be resurrected. The problem is that doing this means killing everyone alive in the process.
- Same Surname Means Related: Toda was the maiden name of Sayama's mother, which makes Sayama suspect there's a connection between Mikoku and his maternal family. Turns out Mikoku comes from Top-Gear, where everyone of Low-Gear had an opposite-sex counterpart. Mikoku is Sayama's female counterpart and therefore, the Toda was her paternal family instead.
- Shadow Archetype: After Shino dies, Mikoku turns into the embodiment of what Sayama could become if he lost Shinjou and tried to reject the world out of grief. It's also more literal than usual since Mikoku is Sayama's Mirror Self from Top-Gear. Sayama directly refers to Mikoku as another version of himself and others.
- Shoo the Dog: Shino thinks Mikoku is always pushing her away, but Mikoku is actually doing it for what she thinks is best for Shino. Mikoku knows their positions as members of the Army put them in danger, so she thinks it would be best for Shino to part ways with her and live an ordinary life away from the Army. In the end, Mikoku's efforts are in vain because Shino can't stay away from her for long and indeed, this results in Shino's tragic death.
- The Stoic: She rarely shows emotion.
- Sugar-and-Ice Personality: She suppresses her emotions and keeps her distance from others. She does have a big soft spot for her adopted family and is described as a kind-hearted person.
- Suicidal Cosmic Temper Tantrum: Mikoku uses Noah with the intention of eliminating the entire world and everyone in it, including herself, just so she doesn't have to deal with the grief of her adopted sister dying because of her.
- Tragic Villain: She becomes one in the final arc of the novels. Mikoku only takes the role of the villain because she has been overcome with grief from losing her precious sister Shino.
- Tsurime Eyes: She has sharp eyes, to reflect her serious and stoic character. Same as Sayama. This could be a hint they are opposite-sex counterparts.
- The Unfettered: She becomes this after Shino dies. Mikoku is ready to do whatever it takes to bring Shino back to life, even if that implies eliminating anyone who opposes her and the entire world because she thinks it doesn't really matter since everyone who died will resurrect if her plan successes anyway.
- Woobie, Destroyer of Worlds: Once Shino dies by her own fault, Mikoku completely loses it and sets out to use the power of Top-Gear's facility Noah to destroy and remake the world into one where Shino can live again.
- You Are in Command Now: With the Army officially defeated and Hajji captured by UCAT, Mikoku is named the new leader and representative of Top-Gear.
Shino Tamiya
Hajji's younger "daughter" and Mikoku's "sister". She possesses a philosopher's stone which allows her to interact and control spirits of small animals like dogs.
- Affectionate Nickname: Ryouko nicknames her "Shi-chan" during the time Shino spends with the Tamiya family.
- The Baby of the Bunch: The youngest member of the Army.
- Charm Person: Her philosopher stone has the power to alter people's thoughts and persuade them to obey her orders.
- Died in Your Arms Tonight: While stopping Mikoku's suicide attempt, Shino gets stabbed by the Totsuka sword and bleeds to death in her adopted sister's arms.
- Disposable Woman: Towards the end of the series, Shino gets killed off with the sole purpose of making Mikoku go mad with grief over losing her dearest little sister, which turns her into a Woobie, Destroyer of Worlds.
- Go Out with a Smile: She smiles gently at Mikoku in her final moments.
- Hime Cut: She has parted blunt bangs, cheek-length sidelocks and long hair. The hairstyle suits her because of her gentle personality and the fact that she usually wears a kimono.
- I Just Want to Be Normal: Unlike the rest of the Army who harbor a deep grudge towards Low-Gear, Shino just wants the fighting to be over so she and her allies can finally have some semblance of a normal life.
- Kill the Cutie: The young and innocent Shino dies while stopping her adopted sister from killing herself. This event breaks Mikoku.
- Kimono Is Traditional: She rarely wears anything other than a kimono.
- Living Emotional Crutch: Shino means everything for Mikoku, something Mikoku acknowledges as a weakness she needs to get rid of. When Shino dies, Mikoku goes off the deep end.
- Morality Pet: Mikoku's constant concern for Shino is what makes her more sympathetic than others in the Army. With Shino's death, Mikoku goes full-on Woobie, Destroyer of Worlds.
- My God, What Have I Done?: She's quite disturbed at herself when she lets slip in front of Kouji Tamiya that she knows Sayama's name and in a panic, uses her philosopher's stone to alter his thoughts only to find out he never suspected her.
- Necromancer: Her philosopher stone allows her to gather and control the ghosts of animals, mainly dogs.
- People Puppets: Her ghost dogs are able to control automatons by possessing them.
- Protectorate: What Mikoku wants more than anything is to protect Shino and keep her safe. Being directly responsible for Shino's death sends Mikoku past the Despair Event Horizon.
- Sacrificial Lion: Shino is killed at the end of the sixth arc while saving Mikoku from her own suicide attempt. Her death is the catalyst for Mikoku Jumping Off the Slippery Slope with her attempt to destroy the world using Noah.
- Satellite Family Member: She's largely characterized through her relationship with her adoptive older sister Mikoku. Since she has no personal grudge against Low-Gear, Shino only cooperates with the Army because she wants to stay close to Mikoku.
- Taking the Bullet: During the representative battle between Sayama and Mikoku, Shino arrives just as Mikoku is about to commit suicide by stabbing herself with the sword Totsuka. Shino embraces Mikoku to protect her, getting stabbed in her stead and dying from her fatal wound.
- Tareme Eyes: She's a young and innocent girl with big, round eyes.
Tatsumi Nagata
A member of the Army and Mikoku's teacher. Until five years ago, she lived at the Hiba Dojo under the name of Miki Hiba and was Ryuuji's older sister figure.
- Action Girl: She's a very capable swordswoman.
- Arch-Enemy: She has chosen Ryuuji as her nemesis and she always opposes him when Team Leviathan fights the Army. Although, Ryuuji's main conflict is that he doesn't want to fight her.
- An Arm and a Leg: She loses her right arm during the final battle against Leviathan.
- Cain and Abel: The Cain to Ryuuji's Abel. She abandoned his family to join the Army and has made clear their former sibling bond means nothing to her, only thinking of him as an enemy.
- Do Not Call Me "Paul": She has to remind Hiba to stop calling her Miki as she goes by Tatsumi now.
- Evil Counterpart: To Hiba. They're trained in the same martial arts style and Tatsumi controls the God of War Typhon to directly oppose Susamikado. She's also the female Hiba from Top-Gear.
- Faux Affably Evil: She smiles and speaks politely to her enemies as she slashes them with her sword.
- How Dare You Die on Me!: She berates Alex when he decides to perform a Heroic Sacrifice since he had promised her to stay by her side and keep her from crying.
- It's All My Fault: She blames herself for the death of Ryuuji's father because she stabbed him for being a man of Low-Gear and she thinks that was why he couldn't escape Top-Gear in time. However, Ryuuji reassures her it wasn't her fault and his father died because he chose to protect his world before saving his own life.
- Master Swordswoman: She's so good that she can take on Susamikado, possibly the most powerful God of War, with her sword.
- Mirror Self: She's Ryuuji Hiba's female counterpart from Top-Gear.
- Same Surname Means Related: Nagata was Ryuuji's mother's maiden name. It's then revealed Tatsumi is Ryuuji's female counterpart from Top-Gear.
- Tragic Keepsake: During the destruction of Top-Gear, Ryuuichi Hiba saved her and left his sword with her shortly before he died. Tatsumi has kept it as a reminder that Ryuuichi likely died because of her.
Alex
The mechanical dragon force of the Army. He's a self-proclaimed "ally of justice". He has been affected by an incurable disease caused by a negative concept, which is why he has been combined with a mechanical dragon in order to slow down the process.
- Always with You: Before he sacrifices himself to help defeat the Leviathan, Alex promises Tatsumi he will always be with her, leaving her a bolt of his mechanical dragon body and the Silent Night song as proof.
- Calling Your Attacks: He always yells the names of his attacks before firing them. When his enemies call him out on it, Alex claims a hero of justice must always announce his special moves.
- Evil Counterpart: He's the Army's mechanical dragon, which makes him directly oppose Heo and Harakawa, the pilots of Thunder Fellow. Taken further by being the male Heo from Top-Gear.
- Heroic Sacrifice: He destroys his mechanical dragon body in a Suicide Attack in order to create a chance for Team Leviathan to defeat the Leviathan dragon and save Low-Gear.
- Justice Will Prevail: What he wishes for is to fight in the name of justice and ensure the people of the world must not experience what he did. He wants to save them, inspire them, and make sure they rehabilitate themselves.
- Large Ham: He shouts the name of his attacks while striking a pose and playing music, as he believes a hero of justice should do.
- Living on Borrowed Time: Alex should have died long ago because of overexposure to activated negative Concepts during the destruction of Top-Gear. His lifespan was prolonged a bit by fusing him with a mechanical dragon.
- Mirror Self: He's Heo Thunderson's male counterpart from Top-Gear.
- Token Robot: Of the main team of the Army. Although, Alex was originally a human too and had to be turned into a mechanical dragon to save his life.
- Was Once a Man: He originally was a human man, but contracted an incurable illness caused by negative Concepts. His mind was transferred to a mechanical dragon to save his life.
Jord
A 10th-Gear goddess who joins the Army at Hajji's invitation. She's Izumo's maternal grandmother.
- Blood Knight: She's always in for a good fight. She likes to pick fights with her allies of the Army just for fun.
- Brawn Hilda: She's large and muscular, having a quite mannish appearance.
- Freudian Excuse: Her close friend betrayed 10th-Gear to marry a Low-Gear man. Jord's daughter followed suit and married Jord's friend's son. Then, both women died because Low-Gear's air is poisonous for 10th-Gear people. Jord wants to destroy 10th-Gear's Concept Core, presumably to prove those things that were taken away from her were nothing.
- The Gunslinger: She primarily fights with guns.
- Gruesome Grandparent: Jord seeks to kill her own grandson, Izumo.
- Never Mess with Granny: She's an elderly goddess and Izumo's grandmother. She's also skilled in Low-Gear weapons and it's impossible to harm her unless one figures out how her concept works.
- Nigh-Invulnerability: No matter what her enemies throw at her, she comes out unharmed. This is caused by her Concept which denies expectations, so no attack can injure her as long as her enemy intends it.
- Not in This for Your Revolution: Jord doesn't care about giving UCAT retribution for the destruction of the Gears nor is interested in the destruction of Concepts. She cooperates with the Army only to get the chance to defeat Izumo (her grandson) and Kazami (the wielder of 10th-Gear's Concept Core).
- Nothing Up My Sleeve: She keeps several firearms hidden in her sleeves.
- Outliving One's Offspring: Her daughter married a man from Low-Gear. Because Low-Gear's air is poisonous for 10th-Gear people, she died soon after.
- Parental Marriage Veto: She was not happy at all about her daughter marrying a Low-Gear man, especially since he was the son of Jord's friend who betrayed 10th-Gear for a Low-Gear man.
- Physical Goddess: While a god from a world based on Norse Mythology, Jord has a physical body identical to that of a human.
- Pride: As a member of the powerful race of gods of 10th-Gear, Jord has one huge superiority complex. She goes as far as refusing to vote either for Low-Gear or Top-Gear because she will never allow 10th-Gear to submit to any other world.
- Red Baron: She's known as Betrayed Expectations, both referring to her past full of disappointments and the concept she uses in battle which denies her opponent's expectations.
- Religious and Mythological Theme Naming: Jord is one pronunciation of the name of the jötunn who is the mother of the thunder god Thor and the personification of earth.
- Smug Snake: She looks down on her opponents believing they can't figure out her concept. Kazami calls her out on how full of herself she is.
- Wild Card: While she works with the Army, Jord does it for the sake of her personal reasons and she isn't loyal to any group in particular.
Supporting Characters
Ryouko Tamiya
The head of the Tamiya family. An absentminded and irresponsible woman, she leaves most of the work to her younger brother. She was in love with Sayama's father, Asagi, and had a fling with Sayama long ago.
- Bespectacled Cutie: She's a pretty ditzy and affable young woman who wears glasses.
- Clingy Jealous Girl: Ryouko states she used to be a "terrible girl" who got mad about Asagi never paying attention to her and she came to deeply resent Yume and Yukio for getting a chance with him. Even though she knew Yukio was the granddaughter of Kaname Shinjou, the benefactor of the Tamiya family, Ryouko never told Yukio about it because she hated the idea of being indebted to her. After they died at the Great Kansai Earthquake, Ryouko came to regret how she behaved with them.
- Cloudcuckoolander: She has a weird thought process.
- Cool Big Sis: She plays the role of a playful and silly older sister figure to Sayama and Shinjou. She also acts the part for Shino when the latter stays at the Tamiya house for some time.
- The Cuckoolander Was Right: Despite how ridiculous her ideas usually are, she was totally right about "Setsu" and his "sister" being the same person.
- The Ditz: She's very absentminded, clueless and careless.
- Foolish Sibling, Responsible Sibling: The foolish to Kouji's responsible. Ryouko is ditzy, irresponsible and childish, Kouji is serious, reasonable and mature.
- Hopeless with Tech: She admits she's no good with machines that have more than two steps. According to her brother, she hasn't learned how to use the video player, the stove, the stereo, and the washing machine.
- Love Father, Love Son: She was in love with Sayama's father. After he died, she slept with Sayama and still shows something of a lingering attraction to him, but it merely comes from his resemblance to his father and she has no intention of pursuing a romantic relationship with Sayama now.
- The Mourning After: Although it was an unrequited love, she never got over Asagi and hasn't fallen in love with anyone else even after years have passed since his death.
- Mrs. Robinson: In the past, Ryouko slept with the much younger Sayama in order to compensate for his father's death. This happened when Sayama was under ten years old.
- Oblivious to Love: She has no idea that Atsuta has been in love with her since highschool.
- Pining After Protagonist's Parent: She loved Sayama's father Asagi, but the feeling wasn't reciprocated. Years after his death, Asagi is still the only man she ever loved.
- Plucky Comic Relief: Almost all the scenes she is in are purely comical.
- Reckless Gun Usage: She carries around a gun despite having no idea how to properly use it. She treats it like it was a toy and tends to lose it.
- Sex for Solace: Years ago, she had a one-night stand with Sayama when both were grieving the death of his parents. They realized it was a mistake and have long moved on since then.
- Shipper on Deck: She supports Sayama's relationship with Shinjou. Funnily enough, she would prefer Sayama to be with "Setsu" instead of "Sadame".
- Single-Target Sexuality: Asagi Sayama was the only man she ever fell for, much to Atsuta's chagrin.
- Student Council President: She was the student council president back in highschool.
- Unrequited Love Lasts Forever: Asagi rejected Ryouko's feelings and married Yume, but Ryouko never stopped pining after him. Years after Asagi's death, Ryouko is still single.
- Womanchild: She acts very childish and immature most of the time and her younger brother has to reprimand her.
Kouji Tamiya
Ryouko's more responsible and reasonable younger brother. He's the one who does most of the real work for the family.
- Cloudcuckoolander's Minder: He's always the one in charge of keeping his sister's absurdity under control and punish her when she does something stupid.
- Foolish Sibling, Responsible Sibling: He's much more serious, responsible and mature than his older sister Ryouko and he's always the one to scold and punish her for her foolishness.
- Mistaken for Pedophile: When Kouji takes an injured Shino to the Tamiya household, Ryouko comments he's probably into little girls.
- Straight Man: He takes this role as the one to deal with his ditzy sister.
Asagi Sayama
Sayama's father who is said to have died at the Great Kansai Earthquake.
- Affectionate Nickname: His wife called him "A-chan".
- An Arm and a Leg: One of his arms was cut off as he pushed Yume and a young Shinjou outside the barrier that would send him into the past along with Noah. And that's why Tenkyou Kinugasa only had one arm.
- Did Not Die That Way: It's stated he was one of the many victims of the Great Kansai Earthquake, but as expected, it's more complicated than that. Asagi was fighting at the battle during the destruction of Top-Gear. There, he was blasted by the spell that sent Noah into the Primordial Chaos and spent the rest of his life in the past under the name Tenkyou Kinugasa.
- Disappeared Dad: He passed away when Sayama was very young.
- Heroic Sacrifice: When it looked like he, Yume and a young Shinjou wouldn't get away in time from the blast that was sending Noah to the past, Asagi pushed the other two out of the barrier into safety while he stayed trapped inside. He was then transported several decades back in time.
- Posthumous Character: He's long dead by the beginning of the series.
- Sdrawkcab Alias: Using Alternate Character Reading, it's discovered the name Tenkyou Kinugasa spelled backwards says Asagi Sayama. This helps Sayama and Shinjou realize the true identity of Tenkyou Kinugasa was Sayama's father who was sent to the past during Top-Gear's destruction.
- Silent Scapegoat: Asagi claimed responsibility for the destruction of Top-Gear by supposedly sending them data to create negative Concepts that would automatically go out of control. The truth is Top-Gear was already experimenting with the creation of negative Concepts even though only Low-Gear is permitted to do something that impossible. Since the Concepts Top-Gear created were unstable, they became the catalyst for that world's destruction. Asagi assumed the blame so Top-Gear wouldn't be blamed for causing its own destruction in their attempt to create a place for Low-Gear in their world.
- Trapped in the Past: During the destruction of Top-Gear, Asagi got send back to around 84 years into the past. He ended up setting up a Stable Time Loop by becoming the man known as Tenkyou Kinugasa.
- Two Aliases, One Character: Asagi Sayama and Tenkyou Kinugasa are in fact the same person in different time periods due to Time Travel.
- Walking Spoiler: As seen by all the spoiler tags in his folder, all information about Asagi besides him being Sayama's late father gives away some of the biggest revelations of the final volumes.
Yume Sayama
Sayama's mother. Sayama states she died after attempting a murder-suicide with him when he was a child, which has given him his frequent chest pains ever since.
- Chekhov's Gun: It's mentioned by her friend Yukio that Yume's name contains the kanji of life in it. This is why Shinjou wearing Yume's ring ultimately is what saves Shinjou's life after she takes an attack from the life-carving name Mikoku under the influence of 2nd-Gear's Concept Core.
- Heroic Sacrifice: Contrary to what Sayama always believed about her, Yume died protecting her son from a radical group of the Army that had come to kill her for participating in Top-Gear's destruction.
- Meaningful Name: The kanji in Yume's name literally translate to "admonition of life".
- Missing Mom: Like her husband, she died when Sayama was a child. The fact she apparently tried to kill him before killing herself gives a good reason why he doesn't exactly like to remember her.
- Never Suicide: The official report of her death is that she killed herself with a blade after attempting to suffocate her son to death. Hajji reveals to Sayama that was just what the police wrongly concluded. The truth is Yume was killed by a radical group of the Army while she was protecting Sayama.
- Offing the Offspring: She held her son tightly in her arms until he passed out in an attempt to suffocate him to death in a Murder-Suicide. Subverted. It turns out it was all a misunderstanding. Yume wasn't trying to kill her son; she was saving him from getting killed with her by some radical group of the Army.
- Posthumous Character: She has been dead for several years by the time the series starts.
Spoiler Characters
Yukio Shinjou
The deceased mother of Sadagiri Shinjou. She was a member of UCAT who was developing a theory to create Concepts until she left to join Top-Gear's UCAT. There, she got married to her own male counterpart. Despite accepting to work as an adviser for the creation of Concepts, Yukio wasn't really interested in it and instead focused on acting as a missionary to spread Christianity in Top-Gear. She was also close friends with Sayama's parents, Asagi and Yume, in high school.
- Always with You: Before she died, Yukio promised Sadagiri that she and her father would always be watching over her.
- Chronic Backstabbing Disorder: According to Hajji, Yukio first betrayed Low-Gear's UCAT by joining Top-Gear's UCAT only to later help Asagi destroy Top-Gear by sending him information he used to send her back activated negative Concepts. The truth is a bit more complicated; Yukio left Low-Gear because she had realized it had a contradiction allowance Concept that gave it the power to create new Concepts. Yukio knew it was impossible for Top-Gear to create Concepts, so she instead went there to act as The Missionary because there was no Christianity in that world. However, the higher-ups kept pressuring her and her husband to create Concepts, which resulted in the activation of the negative Concepts that destroyed Top-Gear.
- Hair Color Dissonance: Like her daughter, Yukio's hair color is described as black even though it has a shade of blue in her colored illustration.
- The Maker: Because of a Stable Time Loop, Yukio is the creator of the Gears' Concepts and the universe itself. Yukio created and completed the concept creation theory which she later took to Top-Gear and developed the negative concepts in the facility Noah. In Christmas of 1995, Noah was sent back to the beginning of time and the negative concepts that were created from Yukio's theory created all the Gears.
- Missing Mom: She died when her daughter was very young.
- The Missionary: Having realized Top-Gear lacked The Bible, Yukio traveled to that world to promote Christianity and build its first church, hoping that would help make Top-Gear and Low-Gear more equal.
- Mysterious Parent: Discovering Yukio's identity and past is the key to many of the biggest mysteries in the story.
- Parental Abandonment: She lost her parents when she was very young and was raised in the orphanage of a church.
- Perpetual Smiler: Yukio rarely stopped smiling no matter the circumstances.
- Posthumous Character: She died during the destruction of Top-Gear ten years prior to the start of the series. Everything known about her is exposed through past records, letters and flashbacks.
- Samaritan Relationship Starter: Yukio initially didn't get along well her male version of Top-Gear and she kept turning him away whenever he approached her to ask her assistance in the Concept creation project. Her opinion of him completely changed when she learned he funded nearly all the money she used to build the first church of Top-Gear. She then agreed to help him in his work and they got married.
- Screw Yourself: She married and had a child with her own male counterpart from Top-Gear.
- Significant Name Overlap: Her husband's full name was also read as "Yukio Shinjou" because he was her male counterpart from Top-Gear. The fact that Yukio kept the same surname after getting married was what caused Sadagiri to doubt Yukio was her mother. This is also a major clue to the revelation of Top-Gear's existence.
- Unwitting Instigator of Doom: Before Noah was sent into the Primordial Chaos to create the Gears, Yukio asked her to "take care of the new world". When Mikoku arrives requesting Noah's help to recreate the world, Noah assumes that must be the way to accomplish the mission her creator left her. Noah doesn't seem to understand resurrecting the world means destroying it and remaking it from scratch.
- Walking Spoiler: Her identity as the mother of Sadagiri Shinjou and her actions in the backstory are all spoilers for the final parts of the series.
Noah
- Airborne Aircraft Carrier: The Noah airship is about as big as an entire city and carries more than enough automatons, Gods of War and mechanical dragons to make an army.
- Gravity Master: She has the power to control gravity, as is standard for automatons.
- Identical Stranger: Having been designated after her creator, she looks identical to Yukio Shinjou and by extension, her child Sadagiri.
- Obliviously Evil: Noah believes that if she helps Mikoku cause the "resurrection" of the world, she would fulfill her purpose to create a new world and bring her creator and everyone who died back to life along the way. What Noah doesn't appear to realize is that doing this would destroy the current world and everyone in it. When UCAT opposes Mikoku, Noah is lead to believe Low-Gear is still Top-Gear's enemy and she must destroy them so she can give birth to a happy world where everyone will come back to life and be equal.
- Overly Long Name: Her full name is 8th Arch-Model Automaton No. 0 of Concept Creation Aerial Ship SSS-X0 Noah.
- Religious and Mythological Theme Naming: She's called by three names; Noah by those who made her in Top-Gear, Babel by those who found her in Low-Gear and Leviathan when she transforms into her giant mechanical dragon form. These are all names of important figures of The Bible.
- Robot Maid: Like the 3rd-Gear automatons, Noah dresses with a maid outfit.
- Some Call Me "Tim": She asks to be simply called Noah because her full name is very long.
- Spaceship Girl: She is basically the AI of the flying ship Noah's control system.
- Time Abyss: Because of the Stable Time Loop, Noah is older than the universe itself.
- Verbal Tic: She ends every of her sentences with "over". Sayama actually asks her to say "over" just to see if she says it twice, which she does.
- Walking Spoiler: Any basic information about Noah gives away the revelations of Top-Gear and many events of the final arc of the series.
- Winged Humanoid: Since she's meant to resemble an angel, Noah has twelve mechanical white wings on her back.
