It is highly recommended that you watch at least the first two episodes of Deca-Dence before continuing to read on. Major spoilers are ahead.
Hundreds of years have passed since humanity was driven to the brink of extinction by the sudden emergence of unknown life forms known as Gadoll. The remainder of population is now limited to the Eurasian continent, where they dwell in a 3,000 meter high mobile fortress called Deca-Dence, which was built to protect themselves from the Gadoll threat.
On the Deca-Dence lives Natsume, a Tanker (i.e., normal human) girl who, after a near-death incident as a child that cost her a limb, dreams of joining The Power, the group of warriors who fight the Gadoll daily and mostly consist of the genetically-enhanced Gears. Unfortunately for her, she gets stuck on armor repair duty, forced to scrub the outside of the fortress clean of any goo that results from the aftermath of fights. One day, when the Deca-Dence gets attacked while she's on duty, another scrape with death has her learn that her surly supervisor Kaburagi is actually a former fighter. Cue some badgering, and he soon relents to teaching her the skills needed to defend her home and join the ranks of The Power herself. At least, that's how things are from her perspective.
In reality, in the latter part of the 25th century, air pollution had reached lethal levels and society broke down. In the midst of all this, large Mega Corps took over and developed cyborg bodies that quickly came to outnumber humans. Eventually, one of these corporations acquired the rights to the remaining unmodified humans, putting a gigantic dome over the continent of Eurasia and making it a wildlife preserve for humans with its own self-governing system... and an entertainment facility for cyborgs. With humans none the wiser, they had become the NPCs in a bizarre mix of LARPing and VR MMORPG, with Gadoll being genetically-manufactured monsters created to keep things interesting and Gears actually being the human avatars of cyborgs who now reside off-planet. Kaburagi is one such cyborg, a retired top player turned MMO-Cleaner who was days away from depleting his real body's power core and deleting himself before discovering that Natsume is actually a "bug" in the system; in this case an Unperson whose embedded tracking chip broke down shortly after the Gadoll attack that took her father and arm. But rather than kill her as per company policy, her strange existence renews Kaburagi's interest in the game and he decides it would be far more interesting to take her on as an apprentice. What follows throws the intended "storyline" of the game going completely off the rails, for better or for worse.
Produced by Studio NUT, the series is directed by Yuzuru Tachikawa (Death Parade, Mob Psycho 100) and aired during the Summer 2020 anime season. The show is licensed in North America by Funimation.
Now has a Characters page.
General Tropes:
- 2D Visuals, 3D Effects: The fortress itself is an entirely 3D creation, as are all the vehicles and the majority of the Gadoll.
- The Alcatraz: The Bug Correctional Facility is built at the bottom of a giant lake. If the atmospheric pressure doesn't instantly crush any escaping cyborg's body then all the Gadoll swimming around and waiting for deployment to the game certainly will.
- Alien Blood: Oxyone, which is green Gadoll "blood" used to power the equipment Gears used to fight them, Deca-Dence's infrastructure, and the cyborgs that play the game.
- Allegedly Free Game: As if Deca-Dence weren't operating on enough levels of evil, its players—including Solid Quake's own employees—are encouraged to funnel their meager earnings back into Solid Quake's coffers via microtransactions.
- Alpha Bitch: Linmei is shaping up to be this, dropping a bug in Natsume's food after she was denied enlistment.
- Animalistic Abomination: The Gadoll come in a wide variety of forms and sizes, looking like insects, crustaceans, mollusks, and reptiles of massive size that have green blood.
- Arc Words: "We exist for the sake of the system." and "The world must be rid of bugs." Both are said by Hugin, the mysterious administrator that oversees the smooth operation of Deca-Dence, and thus the all-powerful AI they serve alongside making sure that Kaburagi continues to do his job as a "bug hunter". He later throws this back in his face as an Ironic Echo: "The world needs bugs."
- Art-Style Dissonance: The cartoonish artstyle of the cyborgs that control the Gears is intentionally jarring to accentuate the brutality of their oppression under Solid Quake.
- Art Shift: The cyborgs that control the Gears are far more cartoonish and thicker outlined than the humans of the setting.
- Ascended Fridge Horror: In Episode 9, Kaburagi and Natsume activate the gadoll's Self-Destruct Mechanism, killing all of them in existence. Some astute viewers pointed out that Pipe is also a gadoll and affected. Sure enough in Episode 10, we have an Empathy Doll Shot of Pipe's now-empty hoodie indicating he was Killed Offscreen.
- Ass Shove: The cyborgs don't actually have such an orifice but as shown in Episode 6, their rear "ports" function as much the same, especially when you have a sadistic warden gleefully shoving low-quality, recycled oxyone into them en masse.
- Attack Its Weak Point: Aside from extreme blunt force trauma, Gadoll regenerate damage so quickly the only way to kill them is to hit them in major arteries with special harpoons to bleed them dry of oxyone. Due to the "Zone" fields they emit as a defense mechanism blocking long-range attacks and the penetrating power of the harpoons, this can only be done at close range.
- Base on Wheels: Deca-Dence is a city on wheels.
- Beam-O-War: Subverted when the mutant colossal gadoll fires a massive breath weapon at the the orbiting space ship, which responds with it's "solid state cannon". The two beams collide... and then the mutant gadoll's beam blasts right through the ship's attack and travels back up it straight to the ship, inflicting heavy damage.
- Black Comedy: Fittingly for a series set in such a bleak, horrifying dystopia, there are numerous jokes where the comedy comes from someone or several someones getting injured, tortured, or humiliated. An example of all three at once is the Bug Correctional Facility, where the warden jams low-quality "recycled" oxyone into cyborgs' "rear ports" all while gleefully saying "Here you go!" as if he were a fast-food worker handing out orders to a line of customers.
- Natsume's Training from Hell Montage also counts, with the initial scenes being her just saved from drowning in water, getting smacked around by a tutorial Gadoll, or screaming as she's strapped to a kite being pulled by Kaburagi's jeep.
- Blackmail Backfire: Natsume tries to use Pipe, Kaburagi's pet Gadoll, to blackmail Kaburagi into teaching her how to fight. Kaburagi's response is to shrug and walk off, and Natsume later apologizes and tells him she wouldn't have done it anyway.
- Bread and Circuses: Deca-Dence mostly exists to distract the cyborg workers from their miserable existence as literal property. That, and squeeze an extra bit of cash out of them through microtransactions.
- Break Her Heart to Save Her: In Episode 4, Kaburagi learns that the upcoming Gadoll nest raid is a hopeless boss fight where the admin fully expects all players to be wiped out, in order to reintroduce retired legendary players as part of a storyline. He visits Natsume in her home, yells at her about the futility of the fight against the Gadoll and her dream of peace, before sabotaging her oxyone tank, rendering her unable to fight.
- Capitalism Is Bad: Deca-Dence's world is a portrait of runaway capitalism at its most dehumanizing extreme, where private corporations amass so much power that one can buy out the entire human race to treat as set dressing for an augmented reality game.
- Casanova Wannabe: Fennel flirts pretty aggressively with Natsume early on, but she is clearly uninterested.
- Central Theme: Going beyond your limits, both those you set yourself and those that were forced upon you by the world.
- Character Customization: There is at least one shop in the Gears' section of the fortress that offers this.
- City in a Bottle: The human NPCs are totally unaware that their entire outside world is one giant playground for cyborgs, run by the Solid Quake Corporation.
- Crapsack World: The Zone where the human population and the Deca-Dense inhabit is a large portion of Eurasia ravaged by Gadoll who threaten the last remain of humanity, which is confined to a single moving fortress. As if that wasn't bad enough this is basically a game controlled by an abominable MegaCorp.
- Crapsaccharine World: On the other end, the cyborg society, which is (largely) confined to a gigantic Generation Ship overflying Eurasia, is actually a colorful dystopian hell utterly controlled by corporations, with the Zone itself used to give their cyborg workers an out for the obscene amounts of stress they're put under. The sheer visual contrast between the two settings in spite of both of them being similarly hellish serves as one of the most inportant thematic foils.
- Damage Over Time: The primary means of killing most Gadoll is by harpooning them in their major arteries, bleeding them dry of the oxyone they need to function.
- Decoy Protagonist: Natsume is presented as the main character for the first episode, but once the true nature of the story's setting is revealed, she's mostly reduced to a sidekick or a viewpoint character. The real protagonist is actually Kaburagi, as it is his actions that have the most impact on the plot and the story focus soon shifts to him.
- Deflector Shields: Gadoll generate a "zone" that acts like this, stopping long-range attacks and forcing Gears to fight at very close range. Solid Quake uses a very similar "zone" barrier to fence off Eurasia from the rest of the world
- Dystopia Is Hard: At the end of the day, Deca-Dence is just a game to Solid Quake, and enforcement of the System's rules falls to troubleshooters finding "bugs" on their own initiative instead of an omniscient surveillance network. Kaburagi can spare an unperson with no one else the wiser.
- Earn Your Happy Ending: After defeating the last remaining Gadoll, the game of Deca-Dence continues to resume work. But this time, it has changed to having multiple family-friendly gaming genres for Gears and Tankers to play in and for everyone to peacefullly coexist. As for Natsume, she gets to reunite with Kaburagi after he was revived thanks to his old backup data.
- Empathy Doll Shot: In Episode 10, we get a shot of Pipe's empty hoodie disguise as proof he was Killed Offscreen after Kaburagi and Natsume activated the gadoll's Self-Destruct Mechanism.
- Face Full of Alien Wing-Wong: As the Gadoll factory is being destroyed, a stray Gadoll wounds a scientist, but gets killed. Midway into the episode, it turns out the wound is a way it reproduces, as the new Gadoll hatches out of the scientist's corpse as a new organism outside of Solid Quake's control.
- First-Episode Twist: The final scene of the first episode has small technicolor robots viewing the main characters. Episode 2 goes on to reveal that after the apocalypse, full-body cyborgs had taken control of the planet and turned it into a hybrid wildlife preserve and MMORPG. All the soldiers we've seen are remotely-controlled avatars, and humans are none-the-wiser NPCs with tracking/control chips lodged inside them. Kaburagi turns out to be one of these cyborgs, whose discovery that Natsume is a "bug" in the system lacking one of these chips piques his interest and gives him a new lease on life.
- Forever War: The Gadoll war is this by intention, since the Gadoll are meant to serve as ubiquitous RPG mobs. Because they're artificially manufactured, there will always be more of them unless the factory that produces them is destroyed.
- From Nobody to Nightmare: A small, weak abused Gadoll minorly wounds a scientist, which results in a new Gadoll that eats its way to becoming the titanic Final Boss.
- Genre Shift: The game Deca-Dence changes genre by the end of the story, with no more Gadoll to fight, it goes from an Action RPG MMO to a family-friendly game which includes actions like minigames, non-fatal fights, exploration, and farming.
- Glass Cannon: A Gear becomes this if they remove their "Limiter." They gain increased fine control and sensory information with their Gear avatar at the risk of damage to their cyborg bodies should they get hit by the Gadoll.
- Goggles Do Something Unusual: Anyone that want's to fight a gadoll wears goggles. They are used to see fluctuations in the magnetic field created by a gadoll's, which allows the goggle wearer to move in and out of these fields to effectively fly. They also appear to allows seeing of Oxyone.
- Healing Factor: The Gadoll's most dangerous ability is their extremely fast regeneration from wounds and dismemberment. So long as they have enough oxyone in their system, they can come back from anything.
- Hellhole Prison: The Bug Correctional Facility is a miserable gulag that seems tailor made to destroy hope. The majority of their days are spent shoveling Gadoll excrement into a giant pit in the center, they are refueled in extremely unpleasant manners using low-quality, "recycled" oxyone from said excrement then zapped to check for "bugged" areas, and are kept in cramped, lightless cells. Add on to the that the inevitable prison gang, guards that don't particularly care to keep things peaceful, the very real risk of being crushed by a falling mound of Gadoll waste, and no hope of release in spite of the administration's claims.
- Hopeless Boss Fight: The blizzard-generating Gadoll at the top of Mt. Everest was created specifically to be this, as part of the admin's plans for a heroic comeback of retired top players after most Gears get wiped out by a powerful foe.
- Hopeless War: Some of the Tanker soldiers, primarily the ones who know how many Gadoll nests have been destroyed in the past to no effect, view the Gadoll war as this. The world outside the fortress never gets any safer no matter how many Gadoll they kill or how many people they lose. Natsume herself has to fight this mentality after clearing out the Gadoll Alpha's nest to no avail.
- Hope Spot: At the end of Episode 5, the Hopeless Boss Fight mentioned above as well as an unfinished Kaiju encounter end up getting defeated thanks to Kaburagi removing all his limiters... however, as everyone revels in their victory, a bunch of gigalinds spawn not too far away. While the Gears revel in this new challenge, the humans are horrified to realize all they've done is for nothing, and Kaburagi is removed from the game and sent to the Bug Correctional Facility for changing the storyline.
- Hunter of Monsters: Similar to Monster Hunter and God Eater, the setting of the story is about fighting off monsters that threaten humanity. The Gears and Tankers are soldiers who fight the Gadoll creatures using enlarged weaponry and use the Gadoll parts they retrieve as resources and fuel. However, the Tankers treat this as a real job, while the Gears only see this as a video game. It's even revealed that Gadoll are purposely being created by the administrators of Deca-Dence to ensure their game continues on. But by the end of the series, the monster hunting game is finally dropped in favor of more family-friendly games.
- Impossibly Cool Weapon: The entire fortress can transform into a cannon. Instead of firing a laser or a rocket, however, it powers an extremely large and devastating mechanical fist.
- Kaiju: The gigalind of the first episode looks like a land whale with the shell of a sea snail that's nearly as big as the whole Deca-Dence. Then killing the S-class boss in the Everest Raid reveals it was the guardian of a sleeping super-kaiju. And then there's all the Kaiju outside of the dome...
- Keystone Army: Destroying the Gadoll factory core somehow causes a chain reaction that destroys every Gadoll on Earth - including Pipe. However, the factory director's personal Chew Toy Gadoll infests him before it dies, which grows into a Gadoll that is separate from the deteriorating Gadoll system and very hungry, becoming the series' Climax Boss.
- Masculine, Feminine, Androgyne Trio: Mindy, Mundy and Mendy, the recurring triplets. Mundy is a muscular man. Mendy is a petite woman wearing pigtails. Mindy is muscular with short short hair and a face closer to her brother's, with her tip-offs of being female being her chest, emulating her sister's midriff-exposing style and her voice.
- MegaCorp: The Solid Quake corporation, which controls Deca-Dence and appears to own at least a portion of the surviving unmodified humans.
- Mix-and-Match Critters: Pipe, the Gadoll Kaburagi took as a pet, looks like a combination of sorts between a grub, a dog, a chameleon and a whale.
- Mix-and-Match Weapon: The main weaponry of Gears and Tankers are various weapons that function like a Harpoon Gun and Pile Bunker combined. The weapons were essentially made to launch large metal needles that are hollow inside so that when they are successfully penetrated in a Gadoll's flesh, it can drain the blood out of it like a syringe. The blood is then absorbed into the fuel packs of the Gears and Tankers to allow them constant flight in the Gadoll's zero gravity zone. The weapons come in different sizes and shapes such as Arm Cannons, spear, and so on.
- Mobile City: The titular object is a giant mobile city that humanity lives in. It's actually run by a MegaCorp that uses it as a hub for their cyborg employees to play an MMO game with Artificial Human avatars that they control remotely.
- Mood Whiplash: In Episode 10, Kaburagi and Donatello have a somber toast with Sarkozy's oxyone moonshine to honor his Heroic Suicide. Shortly after, the two of them complain about how horrible it tastes.
- Nice Job Breaking It, Hero: Kaburagi manages to defeat the Gadoll Alpha at Mt. Everest, what was supposed to be a Hopeless Boss Fight. The celebrations are cut short when its death forces an unfinished giant Gadoll to awaken early, forcing the administration to panic and force Deca-Dence to arm its cannon when it's already low on resources from the initial assault.
- Off the Rails: In-Universe, Kaburagi derails the admins' planned storyline by killing the Gadoll Alpha at Mt. Everest, which was supposed to be a Hopeless Boss Fight. Later, the Tankers, following Natsume's idea, also start to patch up the hole in the Deca Dense, which would throw a wrench in the Population Control the corporation was planning.
- One Nation Under Copyright: The Solid Quake corporation owns not just the whole Eurasian continent, but the rights to all of the unmodified human species.
- Overpopulation Crisis: Not yet, but the administration has concerns about this happening down the road due to the limited land area within the fortress and the lack of Population Control. It's why they organize an event to let Gadoll break through the fortress's armor to cull the Tankers' numbers.
- Phlebotinum Battery: The tanks that Gears and Tankers use to fly and fight Gadoll are powered by the oxyone that serves as the monsters' "blood", but can also absorb the ambient oxyone that powers their "zone" defense mechanisms.
- Proud Warrior Race: The Gears are a bunch of cheerful, technicolor war nuts who treat life-or-death struggles against the Gadoll as a fun game... because it literally is, at least to them.
- Prison Riot: Kaburagi and Donatello's prison gang start one in Episode 9 as part of their plan to destroy the Gadoll production facility, complete with setting fire to the excrement they've been shoveling.
- Private Profit Prison: While the Bug Correctional Facility's stated goal is the rehabilitation of disruptive cyborgs for their reintegration into the Solid Quake company's workforce, it's actually just a pretense to squeeze even more labor out of them with even less compensation.
- Power Source: Oxyone powers everything in this world, from the city to the infrastructure to the Gadoll themselves.
- Railroading: Solid Quake does not appreciate players or NPCs altering Deca-Dence's storylines.
- Reasonable Authority Figure: Minato, one of Deca-Dence's admins, is on friendly terms with Kaburagi and covers for him on multiple occasions, even sparing him from being scrapped after he derails the storyline.
- Remote Body: All Gears are actually flesh avatars being controlled by cartoonish cyborgs who treat them as their playable characters.
- Robots Enslaving Robots: Solid Quake's management is every bit as exploitative of their fellow cyborg as they are apathetic about human life.
- Rocket Punch: The Deca-Dence Cannon fires a mechanical fist (made up of the top of the fortress) the size of a battleship.
- Self-Destruct Mechanism: The Gadoll manufacturing plant has a kill-switch that will destroy all Gadoll currently active in the game, likely meant to be a safety measure if the Gadoll ever went rogue and became a galactic threat.. Kaburagi and Natsume activate it as part of their war against the Gadoll and by extension, the System.
- Serious Business: Cheating in Deca-Dence can result in execution in real life, or a life sentence of enslavement. It's even worse for the Tankers, who are outright murdered on the spot for being bugs in a game they don't know they're the cogs of.
- Servant Race: Tankers are indoctrinated to believe the best course of action they can take is to keep their heads low and support the Gears, who have ever-so-generously offered their protection and the privilege of living in Deca-Dence's fuel tank, through menial labor.
- The cyborgs themselves are little more than property of Solid Quake and other Mega-Corporations, and given Deca-Dence to give them the illusion of control.
- Spanner in the Works: The reason so-called bugs are so feared and hunted down is, aside from ruining the players' immersion, they can seriously disrupt the carefully constructed plots and events the administration designs for them. A key example of this is Episode 5, where to save Natsume, Kaburagi defeats the Hopeless Boss Fight Gaddoll Alpha and accidentally triggers a major, unfinished boss fight that almost ends up destroying Deca-Dence and forcing the admin to scramble.
- Starting A New Account: Kaburagi is forced to make a new account after he's imprisoned in the bug correctional facility. Natsume, naturally, has no idea that Gears can swap bodies, so Kaburagi has to pretend to be an entirely new person when he meets her again.
- To Absent Friends: After the successful escape from the Bug Correctional Facility, Donatello and Kaburagi each enjoy a shot of Sarkozy's oxyone moonshine in honor of his Heroic Suicide. The two of them complain about how bad it tastes shortly after.
- Training from Hell: Kaburagi's unofficial training regime for Natsume involves exercises like strapping her to a kite attached to a jeep, throwing her into deep water to go spearfishing, and forcing her to fight a live Gadoll where she can and repeatedly gets injured.
- "Truman Show" Plot: The Earth has been repurposed into a MMORPG for cyborgs, with humans being the unknowing non-player characters.
- War Is Hell: What Kaburagi tries to convince Natsume of in the aftermath of her first Gadoll fight. Natsume is shocked into silence at first but bounces back from it within a few days.
- Wham Episode:
- Episode 2: Carrying on from the ending of the first, reveals that the Deca-Dence fortress, as well as the entire continent of Eurasia, is really something between a wildlife sanctuary for humans and a real-life video game setting for cyborgs.
- Episode 5: After Kaburagi utterly derails the plot of the Mt. Everest raid, Hugin kills his Tanker avatar.
- What Measure Is a Non-Human?: Inverted, as humans are treated as unimportant non-player characters that flesh out the world of the game. Any humans that ruin immersion or interfere with the corporation's plans for how the game should function are viewed as "bugs" that should be killed without a second thought, and the idea that humans regularly die as a result of Gadoll attacks is considered negligible.
