Character page for the Gundam Build Divers television series.
Voiced by: Yuusuke Kobayashi (Japanese), Erik Kimerer (English)
Gunpla: GN-0000DVR Gundam 00 Diver, Gundam 00 Diver Ace, GN-0000DVR/S Gundam 00 Sky
The main character. A 14-year-old middle school student who joins Gunpla Battle Nexus after watching Kyoya Kujo in a Gunpla Battle.
- Ace Custom: His Gundam 00 Diver is a customized version of the eponymous 00 Gundam from Mobile Suit Gundam 00. It has additional thrusters attached to the GN Drives for extra mobility. Then he upgrades it to the Diver Ace, adding more armor and swords as well as customizing his existing GN Swords.
- Achievements in Ignorance: According to the real life kit's manual, Riku simply gives his 00 Diver a pair of bigger antennae and thrusters underneath his GN Drive compartments merely for aesthetic reasons, but doing so gives it a wider range of radar and flight speed that is closer to the 00 Raiser without realizing it.
- All-Loving Hero: One of Riku's big personality quirks. He loves the world of GBN, the friends he made and his beloved Gundam 00 Diver. However, this sort of quirk allows him to do things without thinking and is easily confused by things more than Black-and-White Morality.
- Always Someone Better: In a shocking turn of events, despite showing off a brand new Super Mode with Higher Than Sky, Riku loses against Tigerwolf.
- Audience Surrogate: In two different ways.
- First, he is a Naïve Newcomer to the world of Gunpla Battle Nexus, meaning he is often the target of exposition by the other characters.
- Second, he represents the fans of the previous seasons and of Gundam in general, having fallen in love with Gunpla Battles after watching the fights of veterans like Kyoya. He is similar to Fumina in this regard.
- BFS: In episode 4, Riku figures out how to bunch both his beam sabers together to generate an extra-long blade.
- Black-and-White Morality: Riku's a poor, simplistic child, thus situations like Ayame working for Tsukasa and Tsukasa's rage against GBN flummox him.
- Blue Is Heroic: Both his avatar and his Gunpla are primarily clad in blue.
- Broken Pedestal: Riku is not happy when he gets the APB about Kyoya and Rommel having Sarah in their custody and saying that they're reforming the Coalition to eradicate the EL-Diver.
- Contrasting Sequel Protagonist: Zig-zagged. Unlike Sei and like Reiji and Sekai, Riku is a Naïve Newcomer to Gunpla Battle. On the other hand, he doesn't have the overwhelming talent that Reiji and Sekai have for piloting and he made his Gunpla himself, much like Sei. Also like Sei, Riku's Gunpla is a customized version of a Gundam used by a protagonist of a major Gundam series. Riku also averts the You Gotta Have Blue Hair of previous protagonists, being a normal brunette compared to Reiji's and Sekai's flaming red and Sei's blue.
- Combination Attack: Riku gets one with Momoka with the Infinity Shot, activating Trans-Am Infinity to kick the Momokapool's Petitekapool at powerful high speeds.
- Cry Cute: In episode 24 no less, after embracing Sarah.
- Dual Wielding: Gundam 00 Diver retains the pair of GN Saber IIs from 00 Gundam, along with two beam sabers. And the Diver Ace upgrade set adds two more.
- The Everyman: Has no distinctive characteristics and is meant to represent the target demographic.
- Fingerless Gloves: His avatar features black ones.
- Godzilla Threshold: After his 00 Diver's GN Drive is damaged due to overtaxing Trans-Am, Riku promises Sarah he won't use this mode until he becomes strong enough to do so. He's ultimately forced to use this mode in his desperate attempt to destroy Tsukasa's Big Zam.
- Heroic BSoD:
- Downplayed. While he doesn't get depressed or anything of the sort, Riku spends some of episode 3 in this due to his loss at the hands of Ogre. It takes a pep talk from Kyoya to shake him out of it.
- Played straight in episode 13 after his fight with Tsukasa.
- Heroes Prefer Swords: His Gunpla is based on one used by Setsuna F. Seiei, THE single most prolific sword user in the Gundam franchise, being armed with two GN Beam Sabers and two GN Sword IIs, so even his guns are swords. He gets even more swords when he upgrades the Diver into the Diver Ace. The 00 Sky downplays this due to incorporating elements of Destiny Gundam, but the Long Rifle can be replaced with another Buster Sword in specific matches.
- Holding Back the Phlebotinum: While the 00 Diver retains the dual GN Drives and should be capable of Trans-Am, the fact remains that the machine itself isn't ready to handle it. Then played straight in time as the machine is improved upon and Koichi outright states that it's ready - only Riku has reached the level that he's realized he can't become reliant on it.
- Idiot Hair: Has a prominent lock of hair sticking way above the rest of his hairdo.
- Idiot Hero: Riku isn't the brightest bulb in the pack. A lot of situations he's involved in is caused by his ability to jump head first into things without thinking things through
- Improbable Aiming Skills: Barely a whole episode in and he's already got a talent for nailing mechs with thrown beam sabers (A callback to Setsuna F. Seiei, whose use of this tactic has taken out GN Fangs, enemy MS, and even a Mobile Armor one time) - this may have been foreshadowed during the soccer game, where he's good enough to nail a goal despite not even being on the school team. He's also stated in his official profile to have excellent motor skills and great dexterity.
- Innocent Blue Eyes: His bright blue eyes emphasis his status as a Naïve Newcomer at the outset of the series.
- Japanese Spirit: Riku runs off of this trope. He has an unclear innate ability that even high-level players simply sense in him, his resolve is unwavering especially in terms of his friends, and his persistence is completely overwhelming. Episodes 12 and 13 are won thanks to a generous use of this trope, turning things around at the last second by just trying harder and become more resolute.
- Kid Hero: Is 14, placing him squarely in the Japanese middle school range.
- Magnetic Hero: Subverted - Magee and Kyoya are the only ones he gets to know entirely by chance, all of the remaining named characters are introduced to him by them. And then deconstructed when the Civil War turns some of them against him.
- Master of None: Invoked in episode 3 with Riku adding a bunch of additional weapons and going through all of them in serial battle mode, just to work out how to do without Trans Am. That's not the way at all.
- Mecha Expansion Pack: The 00 Diver Ace, a jetpack unit which adds knee armor and changes the GN Sword II blades to bigger ones, and throws in two more swords for good measure.
- Mid-Season Upgrade: in episode 13 of 26, after the 00 Diver Ace is badly damaged in his duel with Tsukasa, Riku rebuilds it into the 00 Sky.
- Mix-and-Match Weapon: His GN Sword IIs, which were carried over from the original 00, are both a physical sword and a beam rifle in one.
- Naïve Newcomer: While he is a big fan of Gundam and Gunpla in general, he's a newbie in the world of Gunpla Battle Nexus, easily falling for tricks that more experienced players wouldn't. This is Truth in Television, as many players of new games would be suckered by the things Riku did.
- Pink Girl, Blue Boy: Riku's avatar is the blue to Momoka's pink.
- Primary-Color Champion: His Avatar's outfit features a blue shirt, a red chest piece, and a yellow armband along with blue shoes and white pants.
- Scars Are Forever: 00 Sky has retained 00 Diver Ace's damaged torso hidden behind the clear part as a reminder of Riku's experience.
- Secret Art: Higher Than Sky, which allows the 00 Sky to empower one of its weapons; the large beam sword turns into an energy katana, while the beam cannon becomes a bow and arrow. He can also use it with other Gundams, as shown when he uses with with the AGE-II Magnum to form his own EX-caliber.
- Skyward Scream: Riku does this after finding out that Kyoya, his idol, has taken Sarah into custody and is also referring to her as the EL-Diver.
- Super Mode: The 00 Diver retains the Trans-Am mode of the original 00 Gundam, enhancing its performance threefold for a short time before weakening due to the loss of GN Particles and energy. In a case of Reality Ensues, it turns out that because his build isn't that great, the Trans-Am is highly unstable.
- He gains a second one when, channeled through everyone's feelings about the game, the 00 Diver's GN Drives erupt GN Wings of Light, powerful enough to heal the damage Tsukasa's Break Decal has done.
- The Gundam 00 Sky has two. The first is called "Trans-AM Infinity", a combination of the regular Trans-Am mode of the 00 with the Wings of Light of the Destiny. The second is a mode called the "Higher Than Sky" phase.
- This Is Unforgivable!: What he thinks of Tsukasa distributing Break Decals that risk destroying the GBN.
- Throwing Your Sword Always Works: He has a habit of chucking his beam sabers as projectile weapons. It bites him in the rear when this leaves him disarmed against the Ogre Troll, forcing Riku to borrow one from Yukki's GM III Beam Master to fight back. Notably, this is actually one of the signature techniques of Setsuna, the pilot of the original 00 Gundam, who was so good at it that he could literally take out the AD equivalent of funnels (roughly the size of an MS forearm) in mid-flight with beam sabers and swords twice their size just by throwing them.
- Unskilled, but Strong: Starts the series with no formal training but excellent hand-eye coordination and reaction times.
- Useless Accessory: His avatar has a large knife kept in a scabbard on his back, but he doesn't use it. Subverted in Episode 4 when he uses it to help disable a Leo NPD without using the 00 Diver, as part of his training under Tigerwolf.
- Wardrobe Flaw of Characterization: Riku doesn't tuck in the shirt of his school uniform, rolls up the sleeves and wears his tie loosely, reflecting his relaxed and laid-back attitude.
- Wrecked Weapon: The 00 Diver Ace gets obliterated at the hands of Tsukasa's Astray No-Name.
- Zorro Mark: The 00 Diver Ace has a Finishing Move that cuts up the opponent in a massive A (for "ace").
Voiced by: Natsumi Fujiwara (Japanese), Erica Mendez (English)
Gunpla: RGM-86RBM GM III Beam Master, RGM-89BM Jegan Blast Master
Riku's classmate and best friend. He is very knowledgeable about the Gundam franchise.
- Ace Custom: His GM III Beam Master is painted orange compared to the original's green and white and boasts two missile pods, two larger missile pods, and his custom Changeling Rifle. Although Yukio has access to higher-spec Gunpla and parts, he chooses to use the GM III since it was the first Gunpla he won a competition with, so it's very special to him.
- He later upgrades to the Jegan Blast Master, which boasts a variety of powerful beam cannons from venerated units like the Strike Freedom's Calidus Multi-Phase Beam Cannons, the Double X's Twin Satellite cannon, and the ZZ's High Mega Cannon, making it a walking laser array ready to blast virtually anything apart at long range.
- Berserk Button: Getting anything Gundam-wise wrong. He yells at Nanami for calling the 00 ("Double-Oh") Gundam as the Gundam O2 (like oxygen).
- BFG: Combining the Changeling Rifle with one of the hip boosters creates the devastating Fusion Beam attack.
- Boring, but Practical: His GM III Beam Master lacks most of the bells and whistles of other custom Gunpla, but has stable legs for accurate shooting and equipped with a variety of ranged weaponry as well as his custom Changeling Rifle to pick off foes at range. He also averts Crippling Overspecialization by including beam sabers that are hidden in the armor near the knee joints.
- Brainy Brunette: He's a brunette in reality and is very knowledgeable about the history of Gundam and Gunpla.
- Can't Catch Up: Starts to feel this way during episode 17, when he recalls that he didn't contribute nearly as much as he wanted to during the team's victory in recent battles. Magee suggests that he undertake a quest called Mirror Mode, which is a challenging quest whose only reward is a small button they can wear indicating they beat that mission. But he tells Yuki that many of the veteran Gunpla pilots also took on the mission, and says it helped them out.
- Chekhov's Classroom: He and Do-ji enter the Mirror mission, and find out that some of the objectives are things other than fighting Gundams. In one scenario, they're forced to dodge or catch baseballs batted at them. Later they end up having to solve various wire puzzle traps. The final objective is to apply what they've learned to defeat the final Gundams. They both quickly recall the previous training, such as Do-ji remembering what Yuki said about finding and exploiting weak points, which helps them to defeat their opponents.
- Goggles Do Nothing: His online form has goggles hanging around the neck. Even when piloting.
- Idiot Hair: Something he actually shares with Riku (just not as huge), anytime he's not in that hat.
- I Just Want to Be Special: In episode 17, Yukio suffers a case of Can't Catch Up, noting how everyone is just superior to him, especially Riku. He finally conquers his worries and sets off to build the Jegan Blast Master in response.
- Kid Hero: Is 14, placing him squarely in the Japanese middle school range.
- Mid-Season Upgrade: The new opening reveals that Yukki's upgrading to a Jegan armed with the Twin Satellite Cannons.
- Nice Hat: His avatar features one.
- Not So Different: He and Do-ji both enter the Mirror Mission at the same time in episode 17. Though antagonistic towards each other initially, once the two have a little time to talk, they find out that they both entered this mission in order to catch up to people they deeply respect, Riku for Yuki, and Ogre for Do-ji. In the end they work together to complete the mission, and have newfound respect for one another, along with Do-ji apologizing for his past behaviors.
- Otaku: He's very passionate about Gunpla and even competed in building competitions while chastising Nanami for getting the names of Mobile Suits wrong when she works in a Gunpla store.
- Smart People Wear Glasses: He's very knowledgeable about Gunpla and wears glasses, setting him apart from his Naïve Newcomer best friend, Riku.
- Swiss Army Weapon: The GM III Beam Master's Changeling Gun, which switches from Gatling to straight Beam.
- Wave-Motion Gun: The Jegan Blast Master has the Gundam Double X's Twin Satellite Cannon, which is capable of destroying entire armies in a single blast.
Voiced by: Nene Hieda (Japanese), Cassandra Lee Morris (English)
Gunpla: AMX-109 Kapool (Rented), PEN-01M Momokapool
- Achievements in Ignorance: According to the Momokapool Gunpla directions, Momoka's desire to keep her Gunpla looking as cute as possible ended up increasing its strength and durability.
- Awesome, but Impractical: The Momokapool's Rolling Attack. It uses its spherical body and the flipper-like Iron Nails on its feet to perform a Sonic the Hedgehog-like spin attack, but seeing as she has to spin clockwise, that means its feet can get snagged on protrusions on the ground.
- Subverted - just as ditching her is about to become a Running Gag, she gets an even worse deal by being reduced to a cat-eared Haro when online, but learns early on how to pelt herself at Yukki like a soccer ball. You go, Plucky Girl!
- Played straight by episode 16, which sees her go through a laborious Humiliation Conga.
- Cat Girl: Her GBN avatar is a pink-haired cat girl.
- Calling Your Attacks: She does this, calling out both "Rolling Attack!" and "Belly Beam!" like she's in a Super Robot anime.
- Chest Blaster: Well, BELLY Blaster, really. For an added bonus, the Momokapool's pose mimics the Trope Namer, Mazinger Z.
- Contrasting Sequel Protagonist: Similarly to Riku compared to Sei, Reiji and Sekai, Momoka has major differences between herself, China and Fumina. Where China and Fumina has basic brunette and blonde hair respectively, Momoka is pink. Where China was an artist and Fumina was heavily into Gunpla Battles, Momoka is a soccer enthusiast. The most interesting of the differences is their taste of Gunpla — China's Beargguy III was cute, but could fight with the best of them, Fumina's Star Winning Gundam was a Crouching Moron, Hidden Badass with its Real Mode, but Momoka's Momokapool does away with the killing potential in favor of cuteness.
- Cool Big Sis: Holds this kind of complex towards Sarah, to a massive degree. The biggest indicators of this are when she immediately rushes to the latter's defense in episode 7 upon discovering Sarah doesn't have a Gunpla in a rather assertive manner, and in episode 8 where Momoka is seen feeding Sarah while Riku and Yukio are having small talk with the Archangels.
- Cute Bruiser: Momoka's Momokapool has greatly enhanced speed and strength compared to the original Kapool, but due to her fixation on making it "cute", she lowered its raw lethality by dulling the nails and removing the missile launchers. Despite that, she's still very deadly, easily defeating a customized Zaku II in battle.
- Everything's Better with Penguins: Her Momokapool is a Kapool redesigned to resemble a penguin.
- Everything's Better with Spinning: She attempts this with the Rolling Attack, but she ends up just faceplanting. Thankfully, it allows her to dodge an Action Zaku's beam saber.
- Fastball Special: Turns out the Petitkapool is tough enough to be kicked into the opponent for a Combination Attack - or just kicked across the field to reach the enemy flag at the fastest possible speed.
- Idiot Hair: Three for three! Can you tell they're doing a new Power Trio this season?
- I Know Madden Kombat: Turns out Momoka's sports skills translate very well in the world of GBN as Tigerwolf is impressed with how well she handled her Kapool.
- Meta Mecha: The Petitkapool, small enough to fit inside the Momokapool, and intended as a close-range surprise attack - which is really a massive gamble since that's where the real cockpit is located!
- Modesty Shorts: Her avatar wears these under her skirt.
- Naïve Newcomer: Unlike Riku, who is new to Gunpla Battle, Momoka is new to everything Gundam. She joins our heroes because she doesn't want to be left behind (and picks up a crush on Kyoya).
- Passionate Sports Girl: She's introduced as a member of the school's soccer club and very into the sport, trying to recruit Riku and Yukio in the very first episode.
- Pink Girl, Blue Boy: Her avatar is the pink to Riku's blue.
Voiced by: Haruka Terui (Japanese), Kayli Mills (English)
Gunpla: HER-SELF Mobile Doll Sarah
A mysterious girl that Riku and Yukki find unconscious within Gunpla Battle Nexus.
- All There in the Manual: The Gunpla for Sarah's Mobile Doll self reveals that the mysterious wings she sprouts at the end is actually the Moonlight Butterfly. Thankfully, its effect is tuned down in GBN so she doesn't accidentally break the game again. The documentation also reveals that her gunpla body is supposed to have integrated Beam Magnum cannons built into its arms, and that Sarah doesn't like using them.
- Apocalypse Maiden: Episode 20 reveals that Sarah is becoming this - her data is growing way too fast for GBN to handle and if something isn't done, she will destroy the game.
- Armor-Piercing Question:
- She hits Koichi with two: "Do you love Gunpla Battle? Do you love Gunpla?". It makes him realize he still loves the hobby, but he's scared of expressing it without losing friends again.
- She hits Tsukasa with a question of her own: "Then, why? Why are you crying?" It sets off his Villainous Breakdown.
- Benevolent A.I.: Shows a high level of empathy, readily makes friends with multiple humans, and even agrees to sacrifice her own life when she believes she's endangering the virtual world she was born in.
- Blessed With Suck: She's been able to sense the nature and mechanics of some mechs, raising helpful red flags when around overpowered illegal mods, but they can cause her to get sick. Episode 20 reveals that just being alive is this as she's nothing more than data and her continued existence is threatening everything. A flashback in the sequel series reveals that that the damage her exisence was causing was already a reduced version; her "elder sister" Eve was absorbing the bugs created by her, though it ultimately destroyed her.
- Cry Cute: In episode 24 no less, after embracing Riku in mid-air.
- Cute Machines: Her Gunpla body captures her cuteness and puts it in a tiny form at the same size class as a 1/144 HG Gunpla, with a petite frame that is even more feminine than, say, the Nobel Gundam.
- Cuteness Proximity: Even the opening highlights it by showing her cuddling with a Haro.
- Deus ex Machina: Being an AI created within GBN, Sarah seemingly influences various events for our heroes to raise up in their standing. Unsurprisingly, Ogre ends up accusing Riku of cheating when word gets out of what she really is and forces him into a fight to prove he wasn't.
- Flower Motifs: Has a tendency to show up in fields of flowers and has a flower shaped locket around her neck.
- Glowing Eyes: In episode 3 her eyes can be seen glowing just as she was about the be engulfed in a huge explosion. What this means however is unknown. This returns again in episode 19.
- Go Through Me: She pulls this when Ogre is about to destroy the 00 Diver after it was damaged from using Trans-Am.
- Identity Amnesia: Doesn't know who she is, though still seems to have knowledge of the GBN game, such as what a Gunpla is. This turns out to have been a lie as she didn't want everyone to think that she was strange.
- Idiot Hair: It's very unusual for this many characters in the same anime to have one - of course, it's just her online form. Her Gunpla body has an antennae that corresponds to it.
- Innocently Insensitive: Inverted. She accidentally calls Magee a lady, which leads to him picking her up and hugging her with delight. Played Straight later when she innocently asks if Koichi is what you call "an useless person" when the team is unable to create a force because his rank is too low.
- Instant A.I.: Just Add Water!: Dr. Tori claims she came into being spontaneously in the form of a young girl from the system coalescing millions upon millions of points of surplus gunpla and player data. Of course, whether Dr. Tori is telling the truth or not is another question, but even the idea any AI routine would need the kind of data a giant robot fighting game MMO would be polling to gain Sarah's level of apparent sentience, intelligence or empathy seems outlandish. The sequel, however, implies that her level of sentience came from somewhere.
- Mascot: With Sarah not having an actual Gunpla, Momoka has declared her as this. Later serves as this for the Gundam Base as a "day job" of sorts after coming to the real world.
- Mysterious Waif: Found in the Nexus, with no memory of who she is.
- Mystical White Hair: Has white hair with a slight blue tinge to better illustrate her mysterious Newtype-esque powers.
- Nice Job Breaking It, Hero!: That mysterious Wings of Light that 00 Diver Ace created? That was all Sarah and the energy feathers that scattered across GBN at the end is putting a majorly heavy strain on the game that threatens to destroy it.
- Personality Powers: It seems somewhat like a joke to add something like the Moonlight Butterfly to the Gunpla of a girl that nearly destroyed GBN with solely her existence.
- Proper Tights with a Skirt: Her low cut white dress is complemented with blue tights to illustrate her innocent nature.
- Robot Girl: The crest that her real-world form has on its head evokes this.
- Super Prototype: The sequel reveals that after that are other El-Divers, but Sarah is the first of her kind, and is blessed(And Cursed) With abilities that the others don't have.
- Then it becomes a downplayed example when the sequel reveals that Eve is her older sister, but nevertheless, she still holds abilities and powers that most others don't, and is technically the second of her kind.
- Techno Wizard: Was seemingly able to mentally reach out to Riku through Cyberspace to help him select the perfect Gunpla for him in a real-world store. She also instantly recognizes people by the Gunpla they built, even if she's never met them in person before.
- Tsukasa heavily implies that Sarah actually has the ability to alter the main programming of GBN itself.
- Then there is the fact that she was able to sense Riku's GPD with Tsukasa and give the coordinates to the others. While still being on GBN.
- True Blue Femininity: Her stockings and the inner liner of her dress are blue, as well as her eyes and hair. She also much gentler and more reserved than Momoka, whose avatar is hot pink.
- Unusually Uninteresting Sight: No one seems particularly interested in the fact that she's a naturally occurring AI. Even Ms. Tori is more interested in having people view Sarah as a person and not a program and wants to nurture Sarah rather than being floored that GBN accidentally churned out a sapient AI.
- What Measure Is a Non-Human?: While her teammates and the main developer of GBN consider Sarah a valuable member of the team and someone who deserves to live, Game Master heartlessly refers to Sarah as a "EL-Diver" and tries to get Kyoya to go along with it and, when they come for her, he comes for her with admins armed with guns and the security GMs.
- You Gotta Have Blue Hair: Her hair is a pale blue, though it's not unheard of in the Gunpla Battle Nexus.
Voiced by: Atsushi Tamaru (Japanese), Kyle McCarley (English)
Gunpla: RMS-117G11 Galbaldy Rebake
Nanami's older brother. Koichi was a legendary builder known as K-1 in the days of GBN's predecessor, Gundam Duel. When GBN launched, Koichi's friends left Gundam Duel to play it and he quit Gunpla Battle until Riku rekindled his love for Gunpla.
- Achilles in His Tent: Koichi used to be a 3rd placed national champion and 8th placed worldwide. Yes, he once outranked Magee.
- Beware the Quiet Ones: Koichi is a massive hikkikomori that's the biggest case of This Loser Is You in a Gundam anime - but in his hands the Galbady Rebake is one hell of a beast.
- BFG: The Galbady Rebake can use a back-mounted howitzer cannon that looks ginourmous.
- BFS: His Galbady Rebake carries a massive one, that can transform into a pair of shears that he can use to crush enemy gunpla.
- Big Bad Friend: His former teammate Tsukasa is the Big Bad making the illegal mods that are ruining the GBN game for the first half of the show.
- The Big Guy: Once in combat, the Galbady Rebake's brute strength tactics come to the fore
- Composite Character: His gunpla is a combo of the Galbaldy β from Zeta and the Gundam Gusion Rebake from Iron-Blooded Orphans, with the completed result also having Hades Project Zeorymer aesthetics.
- Contrasting Sequel Protagonist: Koichi is this with Yuuma. Where Yuuma was a blue-haired boy, Koichi is a brunette-haired young man. Where Yuuma was put off of Gunpla Battling because of his defeat at the hands of Adou Saga but still built Gunpla Models, Koichi was put off of Gunpla as a whole because all of his friends abandoned him and Gundam Duel to play GBN and was only convinced to keep building Gunpla to help his sister Naname at her job.
- Drop the Hammer: The Galbady Rebake has a massive hammer wrench that literally crushes you two different ways.
- The Engineer: He's the one who built Momoka's rented Kapool, is the best builder on the team, is the one who teaches the rest of their team advanced building skills, and even scratch-built their shuttle.
- Eyes Always Averted: Is rather shy around strangers, and has a problem talking to or even looking at Sarah, Magee, Tigerwolf and Shahryar when he tries GBN out for the first time in years.
- Genius Bruiser: He's The Strategist, who pilots the heavily armoured and very lethal Galbaldy Rebake.
- Godzilla Threshold: In Episode 21, Koichi hunts down Tsukasa to enact a plan to save Sarah, using a Break Decal and a blank-frame Figure-Rise Standard figure to save Sarah. Tsukasa points out how outlandish his plan is.
- Heroic BSoD: He fell into depression after his friends abandoned him to play GBN. Riku and his friends help him recover from it.
- Hidden Depths: Episode 7 is where we learn just how this massive hikkikomori could ever make the world's top 10 - using a myriad of tactics like wire traps, camouflage, the enemy's own traps and just good old fashioned brute force, Rommel's squad suffers a crushing defeat.
- I Just Want to Have Friends: All his friends leaving his team in a precursor to GBN caused him to stop doing Gunpla battling for years.
- In the Hood: His avatar has a blue hooded cape.
- Luckily, My Shield Will Protect Me: The Galbady Rebake uses the Gusion Rebake's heavy shield. Thanks to the wonders of Iron-Blooded Orphan's canon, the shield is invulnerable to most beam shots, which comes in handy when dealing with Tsukasa's Mass-Diver army.
- Nerd Glasses: Wears big, wide-rimmed glasses to better illustrate he's a hardcore fan of Gundam models.
- Our Elves Are Different: His avatar is a gray-haired, pointy-eared elf.
- Obliquely Obfuscated Occupation: It's not entirely clear what he's been doing for a living, other than some suggestion he uses his skills to build models on commission. We know from Nanami he did this at least a few times for Gundam Base Tokyo, but that alone doesn't seem like enough work to last the 4 years he's been retired from gunpla it battle tournaments.
- Papa Wolf: While obviously the Team Dad by default, Koichi's past heavily hints at his fears of losing his new team again, which goes a long way to explain why the Galbady Rebake is such a dedicated tank.
- Punny Name: In Japanese, his username "KO-1" is pronounced "KO-ichi", since "one" in Japanese is "ichi".
- Scary Shiny Glasses: The panes of his glasses turn completely white when he's depressed or angry.
- Sibling Yin-Yang: While his little sister Nanase is loud and outgoing, he's shy and reserved. Similarly, while he got into Gundam cause he's a Humongous Mecha fanboy, she's only working at Gundam Base Tokyo because she's a Cosplay Otaku Girl.
- Singing in the Shower: Nanami hints Koichi does this in the final episode, usually singing "Anna ni Issho Datta no ni"
- Sleepyhead: He's got constantly messy hair and lines under his eyes, making him always look tired.
- Sympathy for the Devil: Despite everything that he's done, Koichi still tries to reach out to his old friend Tsukasa after the latter's loss to Riku. Unfortunately, Tsukasa doesn't take it well.
- The Strategist: Episode 7 shows his stuff as stated in Hidden Depths, his tactics give a perfect victory.
- Token Adult: The rest of his team are middle schoolers, and sought him out specifically because they needed an experienced gunpla enthusiast to teach them the more advanced ins-and-outs of gunpla construction.
- We Used to Be Friends: Used to be on a gunpla team with Tsukasa, before the rise of GBN drove Koichi to quit gunpla fighting for years to be a Hikikomori and Tsukasa to became an off the grid hacker trying to destroy GBN's playerbase.
- Weapon of Choice: He really likes the Galbaldy mobile suit line from Mobile Suit Zeta Gundam, to the point he is seen with multiple Galbaldy β, won a public tournament with a Galbaldy α, and makes a custom Galbaldy after joining the team.
Voiced by: Manami Numakura (Japanese), Cherami Leigh (English)
Gunpla: SD RX-零 RX-ZeroMaru, SD RX-零/覚醒 RX-ZeroMaru (Shinki Kessho)
A female diver dressed in a kunoichi outfit who was initially part of Tsukasa's Mass-Divers. She was eventually told to join Riku's team in order to serve as a potential Mole, feeding Tsukasa info on various anti-Break Decal operations. She was formerly part of Team Le Chat Noir, before the team was destroyed by a combination of Tsukasa's manipulations and a terrible string of losses. After the Mass-Divers' disbandment following their loss during their war against the Coalition of Volunteers, she reforms and became an official member of Build Divers.
- Aloof Dark-Haired Girl: Played for Laughs — she only does this online, and even then, not the whole time.
- Attack Drones: Her Armed Armor Hattori, a bird-like drone that the ZeroMaru can combine with to form its Real Mode. Given that it's a Unicorn derivative, it can use the NT-D to control other machines' funnels.
- Break the Cutie: Ayame is reduced to tears as Momoka, Koichi and Yukio come to her rescue, making her ultimately realize what a bad decision joining Tsukasa really was.
- Cute Machines: She uses a Super-Deformed ninja gundam.
- Curtains Match the Window: Has a pair of purple eyes to match her purple hair.
- Dark and Troubled Past: She was a solo Diver who joined Le Chat Noir because their leader decided she should. The team started rising up the ranks, but when tougher opponents began to realize what they can do and began overpowering them, the team fell apart, leading to their leader selling their precious unique SD Gundam for a V2 Assault-Buster Gundam which did nothing in changing their fortunes. In a desperate attempt to regain the Gunpla and rebuild the team, Ayame was forced to work with the mercenary who sold them the V2 Assault-Buster, Tsukasa.
- Equippable Ally: In the Lotus Challenge she breaks out one of her new weapons, an SD Gundam that becomes a bladed weapon.
- FaceHeel Turn: Part of her backstory. She joined Tsukasa's side in a desperate attempt to bring back Team Le Chat Noir by winning back her team's Gunpla.
- Flaming Sword: Upgrades her katana sword to combine with her flame scarf in episode 14, allowing her to switch it into a sword covered in red beam flames. She can also apply the flames to her Fuuma Shuriken as well.
- Fuuma Shuriken: ZeroMaru has a giant throwing star mounted on its back.
- Gratuitous Ninja: Pretty much her entire motif, from her Avatar to her Gunpla.
- Good Colors, Evil Colors: The RX-ZeroMaru's Armed Armor bird and 1/144 form originally has a predominantly black motif, indicating Ayame's role as The Mole to Tsukasa. After her HeelFace Turn, she ditches the black for a predominately white color scheme on both.
- Good Costume Switch: After joining Build Divers for good, she switches her armed armor support unit from black to white and modifies the face of her suit's 1/144 form, to make the whole thing look more like the heroic white RX-0 unit 01 Unicorn than the antagonistic black RX-0 unit 02 Banshee.
- Goroawase Number: The name of her Gunpla uses this. In Japanese it's possible to read 0 as maru, and her ZeroMaru is based on the SD version of the RX-0 Unicorn Gundam. In pratice all she did was write out the original model number twice in two different ways.
- HeelFace Turn: Riku and Sarah are able to get to Ayame by promising her a home within GBN and force Build Divers.
- I Am Not Left-Handed: The Zeromaru not only has a Real Mode similar to the Star Winning Gundam, it also has NinTo-Do Mode... or rather, NT-D Mode.
- I Choose to Stay: In episode 14, Aya reveals that Le Chat Noir has reformed once more with their Gunpla returned. When Momoka expresses concern over her leaving, she reveals that she's intending to stay with Build Divers, thus making her a proper Sixth Ranger to the team.
- I've Come Too Far: Her reasoning for why she's preventing Riku from finding Tsukasa. While she never realized the Break Decals would cause so much damage to the game, she did lie and hurt others under Tsukasa's orders. If she switched sides, she would have done all that for nothing.
- Malevolent Masked Men: While working as Tsukasa's mole, she never removes the ninja mask that covers the bottom half of her face. and after her HeelFace Turn, she takes the mask off whenever she's not in battle.
- Me's a Crowd: Not surprisingly, ZeroMaru can execute Bunshin no Jutsu, creating mulitple copies of itself. Aya eventually even weaponizes it, summoning mini versions of ZeroMaru that can transform into sai, machine guns, and so forth.
- Mid-Season Upgrade: In episode 14, Aya upgrades the RX-ZeroMaru with a new paint scheme and improved parts that make it taller and more mobile than a normal SD build. She also adds new weapons and parts to her 1/144 Super Mode as well.
- The Mole: Is sent out by a hooded character to get close to our heroes, after one Gunpla master after another start taking an interest in them. To this end, she allows herself to be recruited into Team Build Divers.
- Most Common Superpower: The Ayame avatar has quite the chest compared to her real life self.
- My God, What Have I Done?: She doesn't say it out loud, but the expression she makes as she watches Do-ji's Break Decal literally chew the scenery apart couldn't be clearer: even if she isn't the one distributing Break Decals, she deeply regrets being involved with them at all.
- Ninja: A master of stealth with a Cool Mask and Scarf of Asskicking to go with it. Even the ZeroMaru has one.
- Not So Above It All: She seems to have an attachment to cute things, such as with the Petitgguy from Episode 8 and Sarah's pet, Mol, in Episode 16. However, Ayame doesn't like publicizing this, so she tries to hide such attachment when encountering both of these things when with Riku and friends... and both times she failed and fell for their adorableness.
- Not So Stoic: In the real world, Aya is actually a pretty shy, polite girl, far from the mysterious, stoic way she acts on GBN as Ayame.
- Pet the Dog: Saved Riku's party from a pair of scammers, the latter in turn being the hooded character -her master's- customers as Mass Divers. Her excuse? She was only sparing their target (Riku).
- Rapunzel Hair: Her avatar's ponytails reach up to her lower legs.
- Redemption Promotion: After she joins Build Divers full time, she redesigns the RX-Zeromaru a bit. It doesn't use the NinTo-Do System in favor of a powerful Psychofield and adds in a new arsenal of weapons.
- Scarf of Asskicking: Her ZeroMaru has a red scarf made out of beam flames to better illustrate her gunpla's supposed to be a badass ninja. She eventually even weaponizes it to grab opponents or turn her other equipment into Elemental Weapons.
- Sixth Ranger: While she joins the team early on, she doesn't officially join the team in a fully heroic capacity until episode 14.
- Sixth Ranger Traitor: To Team Build Divers. As Riku gets closer and closer to discovering the distributor of the Break Decals, she turns on him and tells him that he isn't going any further. After her HeelFace Turn, she is now a traitor to Tsukasa's cause.
- Stealth Hi/Bye: Does this to Team Build Divers when they first meet. To be expected, really, given her Ninja motif.
- Super Mode: Just like the Star Winning Gundam, Zeromaru can mode change from a SD model to a 1/144 real scale model by combining with the bird mecha.
- Transformation Sequence: Zeromaru's mode change from SD to 1/144 real scale gets an extended 30 second sequence starting in episode 14, with multi-colored backgrounds and various close ups of the various parts of her machine switching between modes.
- Wounded Gazelle Gambit: Getting kidnapped by the Arab shiek Mass-Divers was completely premeditated.
- When She Smiles: She drops her face mask in Episode 13, finally showing her face, as illuminated by the sun's rays.◊
- This can also be seen in her flashback in Episode 11 briefly.
- You Are Not Alone: After the events of Episode 12, she attempts to stay away from Riku and the others, but after Kozy and Su show that they got back their old Gunpla and when she realizes that Riku went to great lengths to do so, she realizes she has a team.
- You Shall Not Pass!: As Riku gets closer to Tsukasa, she receives an order to stop him, leading her to say this word by word. After her HeelFace Turn, she pulls this on one of Tsukasa's mercenaries, allowing Riku to finally reach him.
- Zettai Ryouiki: Grade-A with her over-knee boots and stockings in her GBN Avatar. Grade B in her actual school uniform.
Voiced by: Kira Buckland (English)
Picked out by Sarah when visiting a pet shop, Mol-chan is a carbuncle, a rodent-based creature with a jewel in its forehead.
- Just Whistle: Able to emerge from or disappear into Sarah's flower locket.
- Love at First Sight: Sarah is instantly drawn to Mol upon reaching the pet store, a wide-eyed attachment to it.
- New Powers as the Plot Demands: In episode 24 it can inflate itself to about ten feet wide!
- Ridiculously Cute Critter: It's practically two balls of fluff with ears and a face.
- Speech-Impaired Animal: Able to mimic the last thing Sarah says, but that's it.
- Team Pet: A more deliberate one than Sarah, at least.
A young woman who works at the Gundam Base Tokyo. She is friends with Riku and Yukki.
- Alliterative Name: Nanami Nanase.
- Biker Babe: Having never really built Gundams before, her first choice when faced with a mess of spare parts is to build a motorcycle. And boy can she handle it.
- Cosplay Otaku Girl: Unusually for this trope, she may have problems reading the Gundam mecha names but she's completely fixated on the outfits.
- The Ditz: Despite working at The Gundam Base's Gunpla Store, she comes off as a bit spacey in the ways of Gundam, referring to the 00 Gundam as the "Gundam O2". Also, that tomato garden on the roof.
- Moe Anthropomorphism: Played with her diver avatar, which is less the usual diver avatar and more of a typical MS Girl (see the Super Fumina), sporting mobile suit panel parts inspired by Earth Federation mobile suits.
- Shoo Out the Clowns: Her role starts to diminish as Build Divers forms, but she disappears completely after Episode 8. She makes a cameo in episode 13 but doesn't return in full until the next episode, after the midseason climax, and during the denouement.
- Sixth Ranger: Seventh, in this case. She officially joins the game in Episode 19 and desires to build her own Gunpla thanks to what she's done in-game.
Voiced by: Jun Kasama (Japanese), Mark Whitten (English)
Gunpla: AGE-IIMG Gundam AGE II Magnum, AGE-IIMG-SV Gundam AGE II Magnum SV ver.
The leader of Team Avalon and the world champion of Gunpla Battle Nexus.
- The Ace: Kyoya is the reigning Gunpla world champion, good-looking, well-liked by his teammates and adored around the world.
- Ace Custom: His Gundam AGE II Magnum is a heavily customized version of the AGE-2 from Mobile Suit Gundam AGE, featuring an upgraded version of the Hyper DODS Rifle, a shield that acts like a sword, and F-Funnels to hunt down his opponents.
- Anti-Villain: He agrees to keep Sarah prisoner until the Game Master can patch her out of existance, but he's still open to finding a solution that will keep Sarah alive without harming GBN. He runs with this role when he schemes with Riku in trying to save Sarah.
- Attack Drone: The F-Funnels of his Gundam AGE II Magnum are remote weapons designed to ram straight through most opponents.
- Badass in a Nice Suit: Both in his GBN military outfit and his real world tie and waistcoat.
- Big Good: Is working to stop the Mass-Divers because their cheating is causing severe glitches to spread throughout GBN and recruits Riku and Yukki to help him.
- Bond One-Liner: "Farewell, loveless one." to the mercenary in the Providence Gundam.
- Bring It: When Riku makes his challenge to save Sarah, Kyoya willingly accepts it and rallies everyone to their defense.
- Calling the Old Man Out: Kyoya is furious at how inept the GBN administration is over the handling of the Break Decal incidents, unable to comprehend as to why they don't do anything despite even being shown proof of things happening. He tells Game Master all of this, seeing as he's the only one he can confront.
- Challenge Seeker: He finds joy in hard-fought battles and likes nothing more than to find a Worthy Opponent to take on.
- Char Clone: Invoked in episode 3, where he shows up as an ace pilot wearing a Char-esque metal mask to hide his identity. While he fits the "Quattro" combat mentor mold perfectly, the charade doesn't even last the whole episode. Fridge Brilliance alert: since his online avatar is functionally a mask, he already fulfills the primary Char Clone requirement, and does so for this series.
- The Danza: In-Universe example; his ingame first name is his real world first name.
- Expy: Keeping in line with his AGE-02 Magnum's origin, his time spent disguised leaves him somewhat reminiscent of Asemu Asuno while posing as Ash, complete with the Magnum becoming a straight-build Dark Hound.
- Face Framed in Shadow: How his real world self is depicted in the first episode with his Anime Hair indicting that it's him.
- Graceful Loser: When defeated by Riku and Ogre in Episode 24, he simply closes his eyes, smiles, and says, "Magnificent."
- I Am Not Left-Handed: Kyoya didn't want to really do his mission to find Tsukasa because he feared that there were players who became Mass-Divers because they loved the game. When he realized his mercenary opponent in the Providence Gundam didn't give two licks, he shows off his strength and effortlessly curbstomps him by tearing a Break Decal-enhanced Gunpla in half.
- Might Makes Right: He invokes this when he subtly implies to Riku that the only way to sway people's opinions over his plan to save both GBN and Sarah is to defeat the Coalition in a Gunpla Battle.
- Nice Guy: Unusually for a Char Clone (the most heroic of which tend to be Jerks with Hearts of Gold), Kyoya is a friendly man who just wants to ensure that people are able to have fun playing GBN.
- Not So Above It All: Spends way too much time rubbing Rommel's ermine paws - which is an actual thing with Japanese pet lovers.
- Paper-Thin Disguise: When masquerading as a lower level player, he only changes his costume, puts on a mask, and turns his AGE II Magnum into a Dark Hound. He keeps his name and his mannerisms and tries to pass it off as him admiring the champion. It actually does work on Riku and Yuki.
- Reasonable Authority Figure: Despite the pressure mounting on him to just fork over Sarah and allow her to be erased, he's willing to grant Riku and his friends a chance to prove their might and determination to save her.
- Red Baron: "Champion" thanks to his status as the top-ranked GBN player.
- Secret Art: His super move, EX-calibur, a giant golden BFS.
- Screw the Rules, I Make Them!: When Game Master decides to go over his head and delete Sarah while they're all fighting, he learns that all of his administration power are deactivated in the Force Nest, Kyoya having exercised his own privileges to stop that.
- Spin to Deflect Stuff: The F-Funnels can also spin in a cross formation sturdy enough to block direct hits from a missile launcher.
- Super Mode: The AGE-II Magnum SV borrows the AGE-FX's FX Burst; he calls it FX-plosion.
- Suspiciously Similar Substitute: It's hard to not see the similarities between him and Meijin Kawaguchi III from Gundam Build Fighters Try. He is The Ace of Gunpla Battle Nexus, an object of admiration by the rest of the cast, and quickly becomes a Big Brother Mentor to the main characters when he meets them. He even bears a slight resemblance to Tatsuya Yuuki in the real world.
- Worlds Greatest Warrior: He's the top-ranked GBN player in the world and can even defeat players using Break Decals (and the Devil Gundam that wrecked said Break Decal-users) on his lonesome.
- "World of Cardboard" Speech: Gives a nice one to the mercenary in the Providence Gundam before tearing him apart.Kyoya: To be honest, I was somewhat hesitant about this mission. Because I thought there'd be some Mass-Divers who loved GBN. But, that's not how you guys are. I will show no mercy!
- Worthy Opponent: Considers Rommel one and the feeling is mutual.Kyoya: [to Rommel] Your passion and fighting spirit are what drives me!
- You Don't Look Like You: Curiously his offline appearance seems to change between the first and last episode for no apparent reason.
Voiced by: Nanako Mori (Japanese), Erika Harlacher (English)
Gunpla: RGE-G2100C Clanche Custom, AGMF-X56S/a Impulse Gundam Arc
Vice-Captain of Avalon. A serious woman who wears glasses.
- BFG: Her Impulse Gundam Arc wields the Arc rifle that allows her firepower to be on par with Blast Impulse Gundam. If the Arc receive Lancier's Leg Flyer, the Mobile Suit changed into a close-combat type and can use Arc Rifle as a battering club.
- Brutal Honesty: Flat out tells Build Divers that she didn't think they were skilled enough to join the Anti-Mass Diver Coalition was a good idea. Though she follows this by saying she hopes they'll prove her wrong.
- Combining Mecha: The Impulse Gundams Arc and Lancier can swap their Leg Flyers with each other, allowing them to gain each other's specialised attributes. Episode 25, in particular, shows Arc's Chest Core Flyer docking with Lancier's Leg Flyer.
- Guys Smash, Girls Shoot: Emilia's Mid-Season Upgrade is the Impulse Gundam Arc, a blue long-distance unit in contrast to Karuna's red melee-oriented Impulse Gundam Lancier.
- Red Oni, Blue Oni: The serious Blue to Karuna's laidback Red. Their second set of Gunpla reflects this as Emilia has a blue Impulse Gundam compared to Karuna's red/pink version.
- Stoic Spectacles: Wears glasses and easily the most reserved member of Team Avalon.
- Those Two Guys: Regularly seen with Karuna. It's even reflected in their choice of Gunpla as they always choose the same design base (Clanche in the Prologue and the Impulse Gundam from Episode 23 onwards).
Voiced by: Yoshiki Nakajima (Japanese), Sean Chiplock (English)
Gunpla: RGE-G2100C Clanche Custom, AGMF-X56S/l Impulse Gundam Lancier
The other Vice-Captain of Avalon. Generally more laidback than Emilia.
- Big Brother Mentor: The sequel reveals he was this to Hiroto, particularly prior to and during the second Coalition battle, worried that the junior force member was not focused, and recommended him to sit the battle out, though the latter ultimately didn't.
- Blade on a Stick: The Impulse Gundam Lancier uses the Lancier Javelin, a weapon which has the same strength as the Sword Impulse Gundam's Anti-Ship Sword. When Lancier received Arc's Leg Flyer, the Javelin can unleash a powerful beam.
- Butt-Monkey: He's the most relaxed and comic relief of the Avalon team members. In fact according to the Gunpla's real life manual, his Impulse Gundam Lancier was entirely Emilia's idea and non of Karuna's involvement.
- Combining Mecha: The Impulse Gundams Arc and Lancier can swap their Leg Flyers with each other, allowing them to gain each other's specialised attributes. Episode 25, in particular, shows Arc's Chest Core Flyer docking with Lancier's Leg Flyer.
- Guys Smash, Girls Shoot: His Mid-Season Upgrade is the red melee-oriented Impulse Gundam Lancier, in contrast to Emilia's Impulse Gundam Arc, a blue long-distance unit.
- Leeroy Jenkins: Does this in the Prologue by charging into the enemy base ahead of the others (even calling it a race) and nearly gets shot down by an enemy sentinel for his trouble. Emilia promptly scolds him afterwards.
- Real Men Wear Pink: His Gunplas, Clanche Custom and Impulse Gundam Lancier were colored pink.
- Red Oni, Blue Oni: The laidback Red to Emilia's serious Blue. Their second set of Gunpla reflects this as Karuna has a red/pink Impulse Gundam compared to Emilia's blue version.
- Those Two Guys: Regularly seen with Emilia. It's even reflected in their choice of Gunpla as they always choose the same design base (Clanche in the Prologue and the Impulse Gundam from Episode 23 onwards).
7th Panzer Division
Voiced by: Sho Hayami (Japanese), Patrick Seitz (English)
Gunpla: GH-001RB Grimoire Red Beret
Leader of the 7th Panzer Division. He is friendly rivals with Kyoya Kujo.
- Ace Custom: His Grimoire Red Beret is a heavily customized version of the GH-001 Grimoire from Gundam: Reconguista in G.
- Armed Legs: The Grimoire Red Beret's legs conceal some huge and nasty claws.
- Attack Drone: Minimoires, which look like spare Grimoire heads and deploy from the backpack, can function as scouts or be fitted with knives like killer Roombas.
- Badass Adorable: He might have a silly cartoon animal as his avatar, but he's considered The Rival of Kyoya Kujo, the reigning Gunpla world champion.
- Break the Haughty: A mild case. In Episode 7 he sets his rookies up in their debut force battle hiding their affiliation with him, confident that they will win because rookies trained under his force are facing newbies and that they will be rewarded. As the episode goes, his rookie team gets picked off and his smiling face slowly crumbles into him comically "dying".
- Cuteness Proximity: Seems to have a tendency to bring this out in people. Whenever he is around, people just seemingly can't resist to snuggle him due to his cute appearance.
- Combat Pragmatist: He and his team laid traps all throughout the map to catch Team Avalon unawares, including traps to hide other traps. He is also keen enough to not label himself the Flag MS in case he lost his fight to Kyoya, though it ends up backfiring when the Flag MS gets shot down anyways by Kyoya's teammates.
- A Father to His Men: He expects the best from his team-mates in 7th Panzer Division and rewards them for their success.
- Half-Dressed Cartoon Animal: He's wearing a shirt, jacket, and a hat, but everything below the waist is uncovered.
- High-Class Glass: Usually seen with one of these, sometimes several in a row, when out of combat.
- Not So Stoic: In the first sparring battle against Riku's Build Divers, the myriad number of ways his squad gets owned causes Rommel to wilt further and further until he looks like he's in anaemic shock.
- Red Baron: "Clever Rommel", for his unconventional and brilliant tactics. He's also called "Captain Rommel" for being the captain of his team and his militaristic dress and style.
- Shout-Out: His Gunpla is pretty much a homage to red shoulder Scopedog.
- Stealth Pun: His avatar is a play on Erwin Rommel. Ermine Rommel.
- The Rival: To Kyoya Kujo, though Rommel admits that his skills as a pilot are still inferior to Kyoya's, calling him a "monster".
- Talking Animal: Rommel's avatar resembles a human-sized ermine.
- Vocal Dissonance: He might resemble a cute ermine, but he has a deep voice that wouldn't be out of place on a muscled older character. This is especially true in the English dub, as his voice is provided by Patrick Seitz.
- Well-Intentioned Extremist: Sides with the administration over the EL-Diver situation despite being friends with Sarah and considering her to be a life form. In his mind, preserving GBN, a world where those who cannot walk and talk in the real world, such as Rommel's teammate Kurt, can do so in virtual reality, is worth the cost of one innocent life.
- The Worf Effect: He and his team get used to demonstrate the threat of Break Decals after they evolve to the point of giving Gunpla powerful Healing Factors akin to DG Cells, resulting in his team getting wiped. For that matter, as of Episode 24, he and his force have lost each and every onscreen battle they've fought, with the exception of the episode 13 Coalition fight. And even in that fight, he and his Grimoire got literally crushed.
- Worthy Opponent: Considers Kyoya one and the feeling is mutual. They're rivals, but also good friends and confidants.Rommel: [to Kyoya] I must say I admire your strength!
Voiced by: Taishi Murata (Japanese), Doug Erholtz (English)
Gunpla: ZGMF-X20A-LP Gundam Love Phantom
The 23rd ranked Gunpla Battle Nexus player in the world. When not busy with the usual force activity, he spends his time mentoring new players to the game.
- Absolute Cleavage: His unitard is open down to the navel, and the jacket over it doesn't hide that either.
- Agent Peacock: He dresses and acts flamboyantly, but he's the 23rd best Gunpla Battle Nexus player in the world.
- And Your Reward Is Clothes: He's fully authorized to do this for new players, like adding the cat ears to Momoka's Haro form.
- The Bartender: Runs a bar in the real world.
- Bunny-Ears Lawyer: Despite his Camp Gay status, he's actually quite helpful as he volunteers himself as a navigator for Riku and Yukio. In fact, he's ranked 23rd in the world, essentially making him The Ace in their little circle and he has a Fair Play Award as one of his accomplishments.
- Camp Gay: He dresses and acts effeminately, calls himself "big sis" and so on, while also being a buff man with very sculpted muscles. Apparently, this extends to his team.
- Combat Stilettos: Wears those shoes you see in the picture while piloting.
- Composite Character: The Gundam Love Phantom, which has the body, arms and waist of the Strike Freedom, the legs, head and beam scythe of Deathscythe and a modified Noir Striker Pack.
- Friend to All Children: His soft spot for kids is precisely what draws him to the Build Fighters at first.
- Nice Guy: Goes out of his way to defend new players from trolls and predators at no benefit to himself.
- No Sense of Personal Space: With the number of times he's gone Stealth Hi/Bye within inches of our heroes, it's a wonder nobody's suffered a heart attack by now.
- Purple Is Powerful: Magee and his Gunpla are both outfitted with a lot of purples and he's a highly-ranked Gunpla Battle Nexus player.
- Queer People Are Funny: He's responsible for a good number of the show's comedic moments, and doesn't even see combat until episode 10.
- Shipper on Deck: Mostly for Tigerwolf/Shahryar, and Emilia/Karuna one time.
- Sinister Scythe: His Gundam Love Phantom uses parts of the Gundam Deathscythe, so naturally he would pack this. He can throw it like a boomerang to rip through multiple targets at once.
- You Gotta Have Blue Hair: His online avatar has purple hair. Justified by the freely customizable nature of player avatars. Turns out he's got purple hair IRL too.
Voiced by: Junichi Suwabe (Japanese), Kaiji Tang (English)
Gunpla: XXXG-01S2龍虎狼 Gundam Jiyan Altron
Leader of the Toraburyu force and self-styled martial arts master, he may appear to be your generic Old Master hermit but is actually old friends with Magee.
- Animal Motifs: He himself has a strong tiger and wolf motifs (unsurprising, considering his name) which carry over to his Gundam which has tiger and wolf heads on the shoulders in addition to the dragon motif carried over from the original Altron.
- Bare-Fisted Monk: Toraburyu is made up entirely of these - Tigerwolf's own skill level is enough to take on a Gunpla. 'WITH HIS BARE HANDS!''
- Combination Attack: With Shahryar, of all people. By equipping a part of the Seravee Scheherazade he can unleash an empowered Ryukorodo, the Sokyoku Silk Road.
- Determinator: Tigerwolf's attitude. Especially telling when he went after Magee, lost... and kept running after him until he could win.
- Expy: Of Master Asia in terms of ridiculous prowess and a knack for kung-fu.
- Famed in Story: Unsurprisingly for a friend of the 23rd ranked Diver, he's a huge deal in GBN. His school draws challengers who want to defeat him to make a name for themselves and get Dive Points, not unlike schools being challenged in classic kung fu films.
- Nice Job Breaking It, Hero!: Kyoya had confronted Tsukasa and was ready to hear why he hates the game so badly. Sadly, Tigerwolf decides to be the big meathead and leaps at Tsukasa to prevent his escape, instead revealing his real form as a Guest Diver Haro.
- Not So Above It All: After turning Riku down flat, Momo and Sarah start pleading with him at the same time... and take him down.
- Red Oni, Blue Oni: The Red to Shahryar's Blue, right off the bat.
- The Rival: He's one to Shahryar due to their clashing philosophies. Toraburyu considers Shahryar to be a pretentious building snob, while Shahryar says that Tigerwolf's fixation on martial arts diminishes the artful aspect of Gunpla and that Toraburyu is all muscle and no brains.
- Screw the Rules, I'm Doing What's Right!: Realizing his team would never refuse to join the Coalition, Tigerwolf quit his team to join Build Divers in aiding in their rescue of Sarah.
- Secret Art: He has three:
- Ultimate Secret: Ryukorodo: a powerful energy blast that combines aspects of his wolf, tiger, and dragon motifs.
- Raijin Thunder: Two blasts of fire and lightning he can fire after equipping his wolf and tiger heads as weapons.
- Shokan Ultimate Secret: Rikugeki Shoryuda: A blast that erupts from the ground and strikes an immobilized enemy. Only used once, to finish off Shahryar.
- Shout-Out: The animation of Rikugeki Shoryuda, complete with the shot-for-shot look of the pilot (in this case Tigerwolf) and the mecha meditating before firing a dragon aura that ends with the attack's kanji is pretty much taken from Ialdaboth.
- Super Mode: He utilizes the G Gundam-based Meikyou Seishui super mode. Ironically using a Gundam Wing suit.
- Trickster Mentor: He makes Riku and Yuuki do exercises from old kung fu Training Montages, knowing full well that they won't accomplish anything because this is VR. The real point was for them to realize and internalize that GBN is different from reality, which is how you can truly become stronger.
- Weaksauce Weakness: Despite being one of the most powerful Gunpla fighters in GBN, Tigerwolf has a glaring weakness when it comes to interacting with girls, as he doesn't know how to say no to them.
- What the Hell, Hero?: Played for laughs in episode 18, the rest of Build Divers is not happy over the fact that Tigerwolf smacks down Riku in the 00 Sky after the machine was helpless from the backlash of its super attack.
Voiced by: Ryota Ohsaka (Japanese), Todd Haberkorn (English)
Gunpla: GN-1001N Seravee Gundam Scheherazade
A master builder and force leader residing in the neutral Perisian server, Shahryar is no slouch in the battling department either.
- Absolute Cleavage: One of a dozen things he and Magee have in common (though there's plenty that set them apart as well.)
- Actually, I Am Him: It takes until the Shahryar impostor kidnaps somebody for him to reveal himself.
- Agent Peacock: A long-haired, genteel master builder with flowing robes and a huge 1/144 Gunpla that crushes people.
- Always Camp: To a lesser extent than Magee, but still plenty.
- Big Damn Heroes: After Riku and Yuuki are brought crashing down into the sand by the Xamdrag's Super Mode while in Shahryar's mini-Ptolemy, he shows up to confront his imposter and said imposter's buddy, and summons his Seravee Gundam Scheherazade to deliver an absolute Curb-Stomp Battle with a hint of Laser-Guided Karma upon them.
- Fairytale Motifs: His character design and Gunpla are huge Shout Outs to Arabian Nights. His Gunpla shares the name of the narrator of the many stories, the model number has 1001N in it, and Shahryar himself is dressed in exotic Arabian clothing (and is named after a king from one of the stories). His ultimate attack is even called "Alf Layla wa-Layla", which is the compilation's original name as "One Thousand and One Nights".
- Fake Defector: He joins the second Coalition of Volunteers so he can give intel on their tactics to Riku. Of course, he also wants to get a chance to fight Tigerwolf in a battle where Tigerwolf has to go all out. While Shahyr does get the battle he wanted, Kyoya figures out Shahry's deception and defeats him before he can help Riku.
- King Incognito: Poses himself as a regular builder in hopes of unmasking the impostor trying to use his name.
- Little Bit Beastly: His Avatar has ears and a tail similar to a silver fox.
- Mecha Expansion Pack: Right off the bat, the Seravee Gundam Scheherazade is paired with the "Ptolemaios Arms", a mini-Ptolemy that it can equip two ways; the long-range Djinn Mode and the close-range Efreet Mode.
- Power of Love: He believes that Gunpla need to be built with love and passion because the slightest imperfection can greatly impact the Gunpla's performance. Given what we've seen of his Gunpla, that philosophy holds true.
- Red Oni, Blue Oni: The mellow Blue to Tigerwolf's Hot-Blooded Red (and to Magee as well).
- Rich Idiot With No Day Job: Sums up his real world persona.
- The Rival: He's one to Tigerwolf due to their clashing philosophies. Toraburyu considers Shahryar to be a pretentious building snob, while Shahryar says that Tigerwolf's fixation on martial arts diminishes the artful aspect of Gunpla and that Toraburyu is all muscle and no brains.
- Wave-Motion Gun: When fully armed, the four Ptolemaios containers are really light beam emitters that unleash a multicolored rainbow of death. There's also the Ptolemaios Cannon, which is just the backpack in battleship mode deploying a cannon barrel, much like the Trope Namer.
Voiced by: Yoshitsugu Matsuoka (Japanese), Derek Stephen Prince (English)
Gunpla: xvv-xc Zedas, xvt-mmc Geara Ghirarga
A predatory player who targets Riku and Yukki on their first day of the game.
- Bare Your Midriff: Played for laughs with his belly hanging out.
- Beware My Stinger Tail: Do-ji upgraded the Ghirarga tail into a stronger offensive weapon, lengthening it and adding a blade.
- Big Brother Worship: A negative example. He really, really wants to be like his older brother Ogre to the point where he fails to notice his own strengths and, as a result, struggles as a fighter. This leads to him purchasing a Break Decal from Tsukasa. His brother ignoring him entirely in favor of his own thirst for battle leads to him actually activating it.
- Can't Catch Up: At some point, he realizes that the kid who was good enough to beat him on his first day is somehow getting better. This and pressure from his own team shoves him headlong into Tsukasa's schemes.
- Con Man: He tricks new, inexperienced players into getting into Free Battles with him so he can easily beat them and take their points.
- Deal with the Devil: His Geara Ghirarga's customization concept is a Ghirarga Mobile Suit that sold its soul to the devil, an ironic fitting when Do-ji obtained the Break Decals from Tsukasa.
- Dual Wielding: His Zedas retains the palm saber mechanism from Gundam AGE. Similarly, Geara Ghirarga retains the Ghiraspear that separates into two sharp pikes.
- HeelFace Turn: At the end of episode 17, Do-ji apologizes to Riku for his actions.
- Ineffectual Sympathetic Villain: Deconstructed. As seen with his Geara Ghirarga, Do-ji is quite skilled and can make a powerful Gunpla, but he wants to be like his big brother, who can tear through opponents like they were a hot knife through butter. The fact that his major rival, Riku, just sees him as the kid that tricked him on his first day while his big brother sees Riku as someone with awesome potential doesn't help his confidence at all along with the teasing made by Oboro, Nuts, and Rose. That puts him in an I Just Want to Be Special mindset that, in reality, he doesn't need to be in. All it does is push him into a Deal with the Devil
- Laser-Guided Karma: A wannabe Con Man that gets played out himself by Tsukasa. It's practically symbolic.
- Red Oni, Blue Oni: The blue to Ogre's red, also in a literal sense.
- Staged Pedestrian Accident: He pulls this on our heroes back in episode 1, and is implied to have done so several times.
- Unknown Rival: He envies Riku since Ogre recognizes Riku's skill. Riku just remembers him as the kid who tricked him.
- Unwitting Instigator of Doom: Unwitting Instigator of Tsukasa's Doom — thanks to Do-ji using the Break Decal Tsukasa sold him, Hyakki ends up getting replaced with Build Divers, allowing for Tsukasa's downfall.
Voiced by: Wataru Hatano (Japanese), Greg Chun (English)
Gunpla: GNX-803OG Ogre GN-X, RX-78GP02R Gundam GP-Rase-Two
Do-ji's older brother, also known as "Hellfire Ogre". He is obsessed with power and aims to defeat the champion of GBN.
- Achilles in His Tent: Ogre puts his entire team on self-imposed suspension after the events of Episode 9, leading to Riku and the rest of Build Divers joining in on Kyoya's coalition in their place.
- Blood Knight: He's generally only interested in fighting, constantly demanding his opponents to show him their strength so he can get stronger and instantly assuming that everyone else is just like him for playing Gundam Battle Nexus. This comes back to bite him when his battle lust leads his little brother Do-ji to purchase and use a Break Decal just so he'd pay attention to him.
- Defeat Means Friendship: With the exception of Do-ji, all of Hyakki's members are players that Ogre defeated after they put up a worthy fight against him.
- Detachment Combat: The Ogre GN-X can launch its forearms on wires, making use of those beam spikes for a deadly grappling move.
- Dual Wielding: The Ogre GN-X's Ogre Swords, which are more like machetes, and have a Bifurcated Weapon function.
- Everyone Has Standards:
- Despite being a Blood Knight, Ogre refuses to go through Sarah's defenseless avatar to finish off Riku's 00 Gundam. He's also disgusted when one of his opponents resorts to cheating via the "Break Decal".
- When Do-Ji used Break Decal during Hyakki and Build Divers' Force battle, he chose to withdraw instead, thus losing the battle
- Evil Counterpart: Not exactly evil, but try comparing Gundam GP-Rase-Two to Riku's Gundam 00 Sky: both are their original Gunplas being outfitted with a Gundam Mobile Suit (GP-02 and Destiny Gundam) from a different universe and have enhanced versions of Trans-Am. GP-Rase-Two's finisher of pulling out a staff from a pool of lava, not unlike 00 Sky's Higher Than Sky Phase's Finsher Move 01. Its taken Up to Eleven when this kit was further upgraded into GP-Rase-Two-Ten, the kanji for Ten is Japanese for Sky.
- Flaming Sword: His special attack has him dip the Rase-Two's mace in lava, transforming into a double-bladed flaming sword.
- Game Face: The Ogre GN-X's horned headplate drops over its eyes in Trans Am to turn it into a Cyber Cyclops (mentioned in the documentation as "Hitotsume Mode").
- Hour of Power: The Ogre GN-X is able to use Trans Am.
- Katanas Are Just Better: Ogre has a huge one that's always in its scabbard (heavily implying that you should run if he takes it out).
- Mid-Season Upgrade: After the Break Decal incident, Ogre creates a new custom Gunpla, the Gundam GP Rase-Two, which is based on the GP-02A Physallis, but also has the ability to use Ogre Trans-Am.
- Names to Run Away from Really Fast: Ogre, his Diver name that is shared with his first Gunpla. His second Gunpla. GR-Rase-Two is named after Rasetsu/Rakshasa, a man-eating Hindu deity.
- One-Man Army:
- Ogre accepted the meeting with the Mass Divers and waited for them out in the open instead of setting up some kind of ambush - because he can beat them all anyway. It's implied that he was the one who reduced them to their paltry numbers the last time.
- The Cold Open of episode 9 reveals that his team is more or less his support as he takes on a battleship on his own. And trashes it in one hit.
- Red and Black and Evil All Over: The Ogre GN-X is not subtle about this at all.
- Red Oni, Blue Oni: The red to Do-ji's blue, also literally.
- The Rival: Despite not being a Char Clone like Kyoya, Ogre seems to be set up to become this for Riku if the opening, episode 2, and the next episode preview are any indication.
- Sleeves Are for Wimps: Likely because he has spiked elbows.
- Spikes of Villainy: The Ogre GN-X can mimic the Gundam AGE-1 Titus' shoulder spikes.
- Spin to Deflect Stuff: He can pull this off with the Ogre GN-X's two swords.
- The Only One Allowed to Defeat You: Originally aiming to fight the champion Kyoya himself, Ogre comes to view Riku as a Worthy Opponent despite the boy is still a New Meat to the game. But of course, this is also why Ogre and all of Hyakki end up storming the Civil War in episode 24.
- What the Hell, Hero?: He accuses Riku of being a cheater when he realizes that he was distracted by Sarah's disappearance. The ensuing fight satisfies him that he isn't faking it.
Gunpla: MSN-03SL Jagd Doga Thorn, ZM-S22S 凶 Rig Shokew Magatsu, WMS-03NT Maganac Cinnabar
- Bare Your Midriff: Rose
- The Big Guy: Nuts, at least in person (Ogre himself takes over this trope in combat).
- Didn't Think This Through: Rose in episode 19. Repeatedly.
- Expy: Rose is basically a Palette Swap of Chara Soon.
- Guys Smash, Girls Shoot: Rose is designated as the sharpshooter, with the Jagd Doga Thorn carrying a long rifle, and with its funnels retained it can do a lot more shooting on the side, literally.
- Knife Nut: Oboro's Rig Shokew Magatsu is Dual Wielding these.
- Satellite Character: They are Do-ji and Ogre's teammates. Outside of that, they don't have much character.
- Scars Are Forever: Nuts, despite being an online avatar - there's even an oddly realistic case of a scar reaching his pate to create a hairless area.
- The Smurfette Principle: Rose is the one female member of Hyakki.
le Chat Noir/Chat Noir Neo
Gunpla: SD Knight Tallgeese, Wizard Nu Gundam, Kaku (JiaXu) Ashtaron, LM314V23/24 Victory 2 Assault-Buster Gundam (past lineup); Shock Gundam, SG Gundam, SG Char's Zaku II, SG Nu Gundam and SG Sazabi (current lineup)
Ayame's original Force, manning SD Gundams from different continuities. A combination of increasingly aggressive opponents and Tsukasa's machinations caused the Force to disintegrate, but Riku and Ayame's efforts in taking down Tsukasa and all Break Decal use inspired them to return to GBN and give it another go. The result — Chat Noir Neo, a new rookie team with a formidable amount of energy, and a few surprises of their own.
- Ambiguous Disorder: Miyu chooses to communicate with growls behind her tribal-looking mask - because she's socially crippled without it.
- Ambiguous Gender: While Hero easily has one of the manliest outfits among the named characters, episode 17, with Hero joining an all-girl event, affirms that she was a girl the whole time.
- Bedlah Babe: The harem-girl-looking Terra.
- Benevolent Boss: Kozy had no problem with the new conscripts leaving on their own terms... until this extended to the founding members.
- Bratty Half-Pint: Two of them. Then again all of the current lineup is roughly the same size and age...
- Combining Mecha: The Neo team's ace in the hole — all of their SD Gundams turn into one big one!
- Horny Vikings: Hero's outfit.
- Identical Twin ID Tag: Shu and Ron have slightly different helmets.
- Nice Hat: Kozy's healer outfit includes a pope hat. There's also Hawk, the guy in a bowler.
- Pelts of the Barbarian: Hero's outfit is mostly furs. Lip has a lovely wolfskin hood.
- Putting the Band Back Together: Played straight with the return of the original le Chat Noir — with the twist that Ayame opted out.
- Satellite Character: All of them count like this to Ayame.
- Token Mini-Moe: Miyu. That huge tribal mask doesn't do much to hide it.
- Unwitting Instigator of Doom: It was Kozy's decision to switch to a regular HG Gunpla (the Victory 2 Assault-Buster Gundam), which only proved to accelerate their downfall.
Voiced by: Taku Yashiro (Japanese), Khoi Dao (English)
Gunpla: MBF-P02 Astray Red Frame, MA-08 Big Zam, MBF-PNN Astray No-Name
The mysterious seller of the Break Decals. He was a friend of Koichi's during the popularity of the real world model fighting game "Gundam Duel". He deeply hates GBN for replacing Gundam Duel with a purely digital MMO, deeming the entire thing fake. His ultimate goal is to bring "real" gunpla fights back by flooding GBN with cheating, bugs and server outages.
- Ace Custom: The Astray No-Name started as an MBF-P02 Astray Red Frame, one of five (and later quite a few more) mass-produced prototypes for the Astray line of mobile suits from Mobile Suit Gundam SEED Astray. After every defeat in Gundam Duel, he further customized his unit, honing it first into Lowe Guele's own custom version of the suit from Gundam SEED Astray: Princess in the Sky, the Lord Astray, and later into his own Fashionable Asymmetry version.
- Arrogant Kung-Fu Guy: He looks down on GBN players since he thinks the skills they develop in GBN are inferior to the ones he developed in Gunpla Duel. As a result, his loss to Riku leaves him badly shaken.
- Big Bad: At least for the first half of the show, he's the driving force for the sudden rise of Mass-Divers.
- Blood Knight: Heavily shown to be why he enjoys Gunpla Duel over GBN as it allows him to enjoy the battle as he "feels" as it should be played, battle scars and being forced to repair things and all that it entails. Similarly gives this as his reason for helping to save Sarah: It would be boring to just let GBN self-destruct on its own. If it is gonna explode, he wants to do it.
- Break the Haughty: Tsukasa genuinely believed that his skills developed in Gunpla Duel were far superior to the ones GBN players like Riku developed in the virtual world. His loss to Riku in a match of Gunpla Duel shatters his composure and leaves him an angry, shaken mess.
- Bribing Your Way to Victory:
- An In-Universe example, as he sells the Break Decals to players, allowing them to go further beyond their skill level without improving at all.
- It's also revealed he had been doing this before the Break Decals as he had built his own army of Gunpla and was selling them to others. One he sold, a V2 Assault Buster Gundam, was given to Force Le Chat Noir, accelerating their downward spiral.
- Caped Mecha: The Astray No-Name's right side is covered by a set of funnels that mount a beam mantle on it.
- Cryptic Conversation: What Tsukasa's Motive Rant essentially is: He won't stop and say "Hey, I think this game sucks and I hate you guys for picking it up"; a lot of his speech just makes him high and mighty and confuses the hell out of people like Riku and Kyoya, who'd probably understand a lot more if he took the time to explain.
- When he and Riku confront one another, Tsukasa comments on how one of Riku's teammates (heavily implied to be Sarah) has the ability to alter the programming of GBN. Riku is perplexed by this, but Tsukasa assumes he's just playing dumb and refuses to say more.
- Deal with the Devil: A lot of the Mass-Divers want power to hide their Gunpla's flaws. He's all too happy to give them that power.
- Don't You Dare Pity Me!: Does not take it well when someone tries to empathize with him. Both Sarah and Koichi try to do so, and he responds with anger and, in Koichi's case, physical assault.
- Evil Is Petty: He hates GBN and is going to destroy it because it's not an actual Gunpla Battle involving real Gunpla getting wrecked like in his favorite previous version of the game.
- Evil Redhead: Without his hood, he is revealed to have red hair in real life when he confronts Riku and Koichi in Episode 13.
- Fashionable Asymmetry: His Astray No-Name has additional white armor on the left side and gray cloak/rifle Attack Drones on the right side.
- Foil: He's one to several characters:
- To Riku: Both Tsukasa and Riku genuinely love Gunpla Battle; however, Riku loves the world of GBN, while Tsukasa hates it. Riku values the relationships that he's formed through GBN, while Tsukasa is a loner who only seems to care about battle.
- To Koichi: Both Tsukasa and Koichi were fans of Gunpla Duel, the previous format of Gunpla Battle supplanted by GBN. Both reacted to the transition to GBN differently: Koichi became withdrawn and depressed, had to be reminded of his genuine love for Gunpla, and eventually came around to enjoying and thriving in GBN with his new teammates. Tsukasa instead became extremely bitter, justifies his criminal actions with his love for Gunpla, and wants to destroy GBN since he refuses to adjust to the changing times.
- To Kyoya: both men love Gunpla and Gunpla Battle, but while Kyoya believes GBN is a place where people from all over the world can come together and bond over their love for the sport, Tsukasa wants to destroy it and doesn't care that so many people genuinely love it.
- Cross-series, he is basically a dark version of Ricardo Fellini: Both are Gunpla fighters who loved the sport with all of their hearts and who fought with only a single Gunpla which they upgraded over the years as they suffered losses and view it as their partner. But while Ricardo was a happy, nice and outgoing fellow, Tsukasa is bitter and cynical, hopelessly trapped in the past unable to move on.
- Hypocrite: Tsukasa tries to argue that his love for Gunpla justifies his actions. Riku angrily points out that he's ignoring even the idea that anyone else (especially GBN players) could love Gunpla as much as he does.
- In the Hood: In his real-life persona, Tsukasa is seen wearing a hoodie with the hood up over his head. In his GBN avatar, he wears a red cloak with the hood over his head.
- I Gave My Word: Despite his bitterness after his loss to Riku, he returns Le Chat Noir's composite SD Gunpla as promised.
- It's All About Me: Tsukasa's entire motivation for wanting to destroy GBN is because he prefers the earlier Gunpla Duel system to the world of GBN. During his battle with Riku, he basically admits that he doesn't care if multitudes of other people love GBN; it's not what he likes, so he wants to destroy it.
- Killer Rabbit: His hooded GBN avatar actually disguises that he is using a default Bad Purple Haro sprite, which looks downright adorable using the Big Zam to attempt to destroy GBN.
- Loophole Abuse: How Tsukasa got the Break Decals working - GBN was actually built on top of the old programming from the original Gunpla Duel game and expanded on. All Tsukasa did was using Dummied Out data for his Break Decals. They were undetectable because the game literally treated them as part of the game and not a third party hack.
- Moral Myopia: Tsukasa justifies his efforts to destroy GBN with his love of Gunpla Duel. As Riku points out, he's essentially refusing to accept that anyone else could love GBN just as much.
- Nice Job Fixing It, Villain!: By selling Do-ji a Break Decal, he allows Build Divers to replace Hyakki in the Coalition of Volunteers, which ends up saving Ayame and leading to his eventual downfall.
- Nostalgia Filter: The reason for his grudge again GBN. He can't accept that people can be just as happy while playing GBN as he was while playing GBD. We even see that the controls and combat gameplay are essentially identical, meaning he would've easily transitioned from one to the other. The only reason he has for not enjoying GBN is because in his opinion, GBD was 'better' because there were actual stakes that not everyone was willing or able to bear, making his viewpoint come off a Take That! at elitist Gundam fans, especially in the West.
- No True Scotsman: Or in this case, no one who loves Gunpla Battle plays GBN. Riku quickly proceeds to shut him up on this.
- The Only One Allowed to Defeat You: While he would love to let Sarah destroy GBN, he admits it's better if he could do it himself, thus the reason why he opts to help Koichi in saving her.
- Slasher Smile: He bears one as he's battling, showing how much he enjoys Gunpla Duel.
- Stop Having Fun Guy: An In-Universe example. He hates GBN so much that he's willing to destroy it because it's not Gunpla Duel.
- Suicidal Cosmic Temper Tantrum: When Tigerwolf nearly captures him and he escapes, he hops into a Big Zam, sets the Break Decal level on it to "Final" and prepares to destroy the entire GBN in total spite.
- This Cannot Be!: Tsukasa firmly believed that his skills were superior to Riku's. Upon losing, he can only stare in shock at his destroyed Astray.
- Villainous Breakdown: When confronted by Riku and his love of GBN, he starts ranting and raving cryptically about how GBN is false for having no weight in its battles. He officially hits this trope when Sarah asks why he's crying.Tsukasa: I'm... crying? What do you know?!
- He has another one after losing to Riku in Gunpla Duel. Having been convinced that his skills were superior, he's left stunned speechless upon his loss. When Koichi finds him and tries to reach out to him, Tsukasa snaps at him and angrily tackles him, all the while ranting about his frustrations and anger.
- We Used to Be Friends: With Koichi.
A group of mercenary's hired by Tsukasa to help him against the Force Coalition.
- Card-Carrying Villain: They freely admit to not caring about Nexus or Gunpla what so ever.
- Culture Blind: Fitting for those who are only hired for profit, which one of them learns the hard way when he uses a Qubeley Mass Production-type against Ayame, who is piloting a customized SD Unicorn Gundam, which is known for turning a psycommu-type mobile suit's weapons (Funnels) against themselves. This became subverted in episode 14 when all three of them redeemed and started to join the GBN for real, making amends towards Kyoya and finally looking forward to a fair match.
- Defeat Means Friendship: As of episode 14, their experience fighting the Coalition of Volunteers did leave a positive impact as they became official Divers and look forward to a better match by the next time.
- HeelFace Turn: In episode 14, Kyoya tells Riku that the three apologized for their actions and genuinely want to enjoy the game.
- No Name Given: None of them are ever named.
- Only in It for the Money: Are only even playing GBN because Tsukasa is paying them for assistance. One of them even notes that they will get a big bonus for defeating big named Divers.
Voiced by: Eiji Takemoto (Japanese), Armen Taylor (English)
The face of the admins of Gundam Battle Nexus. Game Master's avatar is modeled after the GunDivers from SD Gundam Force.
- Badass Fingersnap: Does this to declare the Build Divers as the winner of the battle upon seeing Riku and Sarah's reunion.
- Big Damn Heroes: During the final battle against the Raid Boss, Game Master shows up right when the fight seems hopeless and uses debug missiles to cut off the Raid Boss's regeneration.
- Everyone Calls Him "Barkeep": He's the apparent master of the game. So he's the Game Master. It seems to be his actual GBN name. Subverted when Kyoya addresses him by his real name, Katsuragi.
- Heel Realization: After Game Master witnesses Riku and Sarah's tearful reunion, he realizes that Sarah is indeed alive and declares Build Divers winner of the battle in accordance with the battle's rules, despite having previously attempted to go behind Kyoya's back and delete Sarah.
- Inspector Javert: He's not wrong when he's determined the cause of the bugs, but hunting it down puts him directly against the main characters. Conversely, back during the Break Decal incident, despite people literally coming to him and admitting what they've done and people showing video footage, he absolutely refuses to charge them with anything because the game didn't register it.
- "It" Is Dehumanizing: Refuses to call Sarah "her" or even use her name, instead referring to her as "it" and "a bug".
- Just Following Orders: Justifies killing Sarah as it is his job as an admin to keep the servers running.
- Police Are Useless: For a measure of "police," of course. As an admin, he keeps GBN running and enforces its rules, but he was utterly unable to do a thing regarding the Break Decals as they left behind no hard evidence.
- Punch-Clock Villain: By the end of the season, he seems to settle into this slot. He isn't inherently trying to be destructive like Tsukasa, he just wants to do his job of keeping GBN running, and the appearance of an AI isn't going to stop that.
- Screw the Rules, I Make Them!: Despite Kyoya and Riku wanting to decide on Sarah's fate from a Gunpla Battle, Game Master decides to go over all of their heads and just go and delete Sarah himself. Too bad for him Kyoya decides to invoke this trope as well to stop him.
- Took a Level in Idealism: Is one of the major factors in helping out against glitched Raid Bosses. His reason? He wants to see from Riku's point of view regarding their possibilities.
- Transforming Mecha: His avatar can transform into a helicopter mode for combat.
- Villain Has a Point: As it causes increased levels of bugs and crashes in GBN's servers as time goes on, Sarah's existence does indeed threaten the ongoing access to a product accessed by 20 million customers.
- What Measure Is a Non-Human?: He wishes to delete the EL-Diver. It doesn't matter if it's sentient, he just sees it as a bug that needs to be patched. This is further shown when he confronts Ms. Tori and she tries to explain that what he wants to delete is a living being.
- What the Hell, Hero?: He's not happy that, on the cusp of just being done with the EL-Diver's threat, Kyoya and Riku are ready to put GBN's entire existence on the line.
Voiced by: Mai Nakahara (Japanese), Ryan Bartley (English)The original source code developer of GBN using the programming and other elements from the Gunpla Duel system just before it was shut down.
- The Atoner: She admits that being the source code developer of GBN, the server load caused by Sarah is partly her fault and The Reveal that Break Decals only exist because of her reuse of GPD software elements drives her even harder to make things right.
- Big Good: She acknowledges the mistakes in Game Master's judgment by stepping up to the plate.
- Killer Rabbit: Appears online as a yellow bird avatar that secretly has a One-Winged Angel form.
- Promotion to Parent: She's the closest thing Sarah has to a mother.
- Punny Name: Miss Tori sounds a lot like Mystery, does it?
Voiced by: Kenji Hamada (Japanese), Sean Chiplock (English)One of the most regular GBN users, if not the most prolific. A Dive avatar based on Patrick Colasour from Mobile Suit Gundam 00, this person has been seen regularly in GBN, mostly in the Citadel but sometimes stepping up to the plate whenever a massive threat to GBN looms... regardless of whether or not he can match it.
- Butt-Monkey: Even animals from a different continuity are out to give him a hard time.
- Earn Your Happy Ending: A recurring theme in some of his appearances. Even a video presentation on how serial battles work depicts him being put through the wringer before reaching "Victory Royale".
- Fiery Redhead: Be it a serial battle, a martial arts class or even an out of control raid boss, you can count on Patrick Colasour to do his part in some capacity.
- Memetic Bystander: Invoked and enforced.
- Suddenly Voiced: In the first coalition battle, and then the finale.
- Even more sudden in the official dub, where he's heard in episode 2.