* AngstWhatAngst: Eiji has no family, job, or ambitions, but he doesn't really attach any importance to those things so it doesn't bug him. [[spoiler: However, he's often haunted by memories of a girl he'd befriended on his travels that [[ILetGwenStacyDie he was unable to save.]]]]
* BigLippedAlligatorMoment: Even with all the weirdness rampant in #27, one moment stands out: two random women come across the Squid-Jaguar Yummy and smack it around, then disappear before Ankh and Eiji get to it. That's really it -- the women are only in the episode [[{{Pun}} because their names contain the kanji for '1000'.]]
** It's more the fact that they beat the crap out of it than they appeared, as it did mistake them for Kamen Riders.
** Why does the Yummy belonging to the former Shocker Mook spawn a couple of ObaSan?
** Then there's Eiji [[spoiler:resurfacing in Brazil]] at the end of ''Movie Wars Core'', though it leads into a BrickJoke as [[spoiler:Chiyoko shows up after a sign at Cous Coussier stated "On Vacation"]].
* CompleteMonster: While the show took a balanced look at {{greed}} and showed it did not need to be bad, these three demonstrate the worst elements of it:
** [[EvilGenius Kazari]], the [[CatsAreMean Feline Greeed]], is TheChessmaster responsible for many atrocities throughout the series. Of the [[BigBadEnsemble five original Greeed]], he has by far the most horrific way of making Yummy[[labelnote:MISC. INFO]] Yummy are MonstersOfTheWeek created by the Greeed from someones personal desires or greed[[/labelnote]] by implanting them within their host and controlling the host like a puppet, in some cases [[AndIMustScream while the host is conscious the entire time]]. After a while it consumes and traps them inside while they are fully aware of what is happening to them. Kazari's actions in the series proper are worse. He [[spoiler:used his own compatriots Mezool and Gamel as guinea pigs to see what would happen if a Greeed absorbed Core Medals that weren't their own, and was unfazed by there deaths, using this opportunity to absorb their Cores and become stronger. He later raised Lost Ankh as his own personal brainwashed warrior and helps Dr. Maki in trying to destroy the world]]. Sadistic and uncaring, even his own kind despise him for what he is.
** The aforementioned [[MadScientist Doctor Kiyoto Maki]], the DragonInChief to Kazari, is a prime example of what happens when [[TheSociopath antisocial behavior]] goes off the deep end. Before the day of his sister [[{{Jerkass}} Hitomi]]'s wedding, Maki burns his sister to death in her sleep just because she was going to abandon him. He then represses these memories and helps a MadBomber hosting Mezool's Yummy carry out attacks just to see the Yummy grow, not caring who dies in the process. When the swarm of Yummy hatches, he remorselessly locks his workers inside with them and watches the Yummy slaughter his colleagues. When he teams up with Kazari, his memories of Hitomi resurface, driving him to [[OmnicidalManiac destroy the world]]. True to his personal philosophy that "something's true value is only known when it ends", he absorbs five Purple Core Medals to begin transforming into a Greeed himself, the Dinosaur Greeed. Because the core medals make up the essence of a Greeed and give its user Greeed powers, Maki spawns Yummy that are omnicidal, with Maki finding their rampages to be merely "interesting". He also [[TheStarscream has no sense of loyalty to his allies]], as [[spoiler:Kazari learned the hard way when Maki impales him and rips all his cores out of him]]. Near the climax of the series, Maki gives two of his own Cores to Eiji (Kamen Rider OOO) solely to accelerate Eiji's greeedification and tosses the remaining Core Medals from the other Greeed into Uva to forcibly set his ultimate plan of destroying the world into motion.
** [[PredecessorVillain The original Kamen Rider OOO]] and the GreaterScopeVillain of the entire series was an ancient king of a lost civilization who wanted power over anything else. He had three alchemists and Gara create five sentient creatures, the aforementioned Greeed, for the sole purpose of killing them off to reach his goal of [[AGodAmI becoming an immortal god]]. After the alchemists and Gara succeeded, he [[YouHaveOutlivedYourUsefulness betrayed them and turned them into cell medals]], with [[AndIMustScream Gara still being conscious in this state]]. He then stole the core medals from the Greeed even though that would kill them over time. He used this power to take over a large portion of Europe and was well on the way to [[TakeOverTheWorld taking over the world]]. The prequel novel by Nobuhiro Mouri expands on his actions and shows that he cloned himself to attack neighboring countries; burned down villages that opposed him; invaded enemy camps using subterfuge; and used earthquakes and tsunamis to wipe out the Spanish Armada. After Ankh betrays the other Greeed by working with him, he [[ChronicBackstabbingDisorder double-crosses Ankh and stabs him in the back]] for his Core Medals and causes all the Greeed to be sealed away [[ItsAllAboutMe just so he could have the medals for himself]].
* DracoInLeatherPants: The Greeeds: Uva, Kazari, Mezul, and Gamel. In spades. Also, Dr. Maki believe it or not for being utterly hilarious, especially if his doll's knocked off his shoulder.
* EarWorm: The opening theme, "[[http://blip.tv/kamen-rider/anything-goes-mv-4410884 Anything Goes]]". Despite it being so happy, jumpy and weird compared to the opening themes of Decade and Double, you can't help but listen to it over and over again.
-->''You count the Medals: one, two and three! Life goes on; anything goes! Coming up, OOO!''
** Just listen to the [[http://www.youtube.com/watch?v=qCgCEZmLsMo SKA version of Regret Nothing ~Tighten Up~]], you can tell Kushida had alot of fun with that one.
** [=PuToTyra=] [[http://www.youtube.com/watch?v=zIz1W_pGqq4 PuToTyrannosaur!]]
** The OST has lot of [=BGMs=] that, once listened, won't be leaving your head anytime soon. Even more so if you're familiar with the series to know in which context each track is used.
*** T#08: "[[http://www.esnips.com/doc/72839bd8-2b02-4f10-b286-033331179150/Kamen-Rider-OOO---The-Schoolgirl-of-My-Dreams The Schoolgirl of My Dreams]]". Possibly Hina's leitmotif. For quite a calm guitar track, it ironically got a heavy, emotional piano remix in the form of T#50: "[[SugarWiki/AwesomeMusic Brother and Sister]]".
*** T#10: "[[http://www.esnips.com/doc/dae8aaf5-6708-48ac-98ba-02cf207df116/Kamen-Rider-OOO---Hina-the-Schoolgirl Hina the Schoolgirl]]". A humorous remix of T#08; it even has somebody making groaning sounds in the background.
*** T#12: "[[http://www.esnips.com/doc/73f966d8-0a61-4606-afbe-8dd07b5e8109/Kamen-Rider-OOO---Ankh-the-Greeed Ankh the Greeed]]". Ankh's leitmotif styled after classic Egyptian music.
*** T#14: "[[http://www.esnips.com/doc/dba36023-6f87-493d-8981-0e3f6ff8b4ce/Kamen-Rider-OOO---Ankhs-Secret Ankh's Secret]]". A slower remix of T#12.
*** T#19: "[[http://www.esnips.com/doc/ac534b53-c1c4-4042-8337-1cf7d25ae970/Kamen-Rider-OOO---Enter-the-Can-droids Enter the Can-droids]]". A cutely robotic tune for the kids' favourite robot buddies.
** The OOO Scanner managed to find different ways to be catchy with its Combo tunes. By extension, Akira Kushida's background rhythms in the Combo {{Image Song}}s as well.
*** '''TAKA! TORA! BATTA! TA-TO-BA!''' '''[=TaToBa=]''', '''TA-TO-BA!'''
*** '''KUWAGATA! KAMAKIRI! BATTA! [Buzz!] Ga~ta-Gata-Gata-Kiri! Ba! [=GataKiriBa=]!'''
*** '''LION! TORA! CHEETAH! [Roar!] [=LaTah=] [=LaTah=]! [=LaTora=]~~Tah!'''
*** '''SAI! GORILLA! ZOU! [Stomp!] [=SaGoZo=]... SAGOZO!'''
*** '''TAKA! KUJAKU! CONDOR! [Crow!] Ta~Ja~Doru!'''
*** '''SHACHI! UNAGI! TAKO! [Splash!] Sha-Sha-[=ShaUTa=], Sha-Sha-[=ShaUTa=]!'''
*** '''PTERA! TRICERA! TYRANNO! [Screech!] Pu-To-Tyrannosaurus!'''
*** '''COBRA! KAME! WANI! [Hiss!] [=BuraKa=]~~WANI!'''
*** '''TAKA! IMAGIN! SHOCKER! Ta-Ma-Shii! [=TaMaShii=], Ta-Ma-Shii! Rider~ Damashii'''!
*** '''SUPER, SUPER, SUPER! SUPER TAKA! SUPER TORA! SUPER BATTA!''' '''Su~per [=TaToBa=]''', '''TA-TO-BA! SUPER!'''
* EnsembleDarkHorse: Akira Date, due to his rather laid-back behavior and general masculinity. Probably why he was brought back for the final eps.
* EpilepticTrees: Since the beginning, many people began creating theories about the OOO Driver being a DeadlyUpgrade, who the Original OOO was, and how it will effect Eiji, with a popular theory being that Eiji would turn into a Greeed. [[spoiler: Surprisingly, they're correct about the latter, but it's not the OOO Driver that's doing the conversion. That would be the Core Medals inside Eiji.]]
* GameBreaker: [[color:purple:[=PuToTyra=]]] Combo.
** [=GataKiriBa=] counts too, not only because of its duplication powers, but it can also split itself into 8, with each transforming into other different combos.
* HilariousInHindsight: In the advertising for the ''[[Series/KamenRiderDenO Cho Den-O Trilogy]]'', Momotaros says of the trilogy's ColorfulThemeNaming "Think of a traffic light!" Now we have OOO, who has himself been nicknamed Kamen Rider Traffic Light.
** Hina is one letter away from another [[Series/KamenRiderDenO super strong, blackhaired young woman who can beat up a monster singlehandedly.]]
** It's hard not to be reminded of ''ComicBook/ScottPilgrim'' with the medal motif, and bad guys bursting into coins once beaten.
** "''[[Anime/DigimonTamers Giru?]]''"
** [[color:red:Red]], [[color:blue:Blue]], [[color:gold:Yellow]], [[color:purple:Purple]], [[color:Gray:White]] [[note]][=SaGoZo=] plays around with the white-gray spectrum, but mostly light.[[/note]] and [[color:green:Green]] monsters, and Rider Forms drawn from their powers? [[Series/KamenRiderDenO Hmm...]]
*** As the ImageSong and ending song sung by the main character and his red demonic partner who is the source of power for the main Kamen Rider's red form, "Time Judged All" is, in concept, not unlike "[[Series/KamenRiderDenO Double Action - Sword Form]]".
** One of the Net Movies for Series/KamenRiderDecade involved Film/{{Shin Kamen Rider|Prologue}} and his ImagineSpot, wondering what it'd be like if his show took off. Episodes 21 and 22 provide a somewhat twisted picture.
** We've had Dr Maki leaving the Kougami company to form his own faction with the younger-looking Kazari and [[spoiler:Lost Ankh]] in the form of a small boy, not long after the fate of ''a certain other'' Series/TwoAndAHalfMen was in question.
*** And the final fight is [[spoiler:Eiji with Ankh reduced to Core medals vs. Maki,]] essentially Two And Bits of a Man.
** [=ShaUTa=] Combo's theme song title, "Shout Out", is bound to make many a troper chuckle.
** Birth's theme "Reverse/Re:birth" sounds quite a call back when it is considered that Series/KamenRiderBlade's resident Gunslinger Garren's actor sang an ending theme for his series, called rebirth.
** The OOO chapter in ''Movie Wars Core'' is subtitled ''Nobunaga's Desire'', which may bring to mind one of {{Koei}}'s strategy game titles, ''VideoGame/NobunagasAmbition''.
** One of those "weird Japanese inventions" often circulated on the 'net involves a device women can use to outwit stalkers, a handbag that unfolds into a vending machine disguise. Which is exactly what the [=RideVender=] does.
*** You know who else was famously disguised as a vending machine? [[{{Film/Transformers}} Dispensor.]]
** The animals Kazari's Core Medals are based on, [[color:goldenrod:Lion]], [[color:gold:Tiger]] and [[color:yellow:Cheetah]], appeared as Mecha in ''Series/JukenSentaiGekiranger''.
*** Ditto for Giru's Medals, Ptera, Tricera, and Tyranno for ''Series/BakuryuuSentaiAbaranger''
** There was quite a bit of negative reaction over [=PuToTyra=], the purple form, being designated as the "Ultimate Form" over the already-impressive [=TaJaDor=] (which was touted as such in ''Movie Wars Core''). Fast forward to the finale, and [[spoiler:[=PuToTyra=] gets [[TheWorfEffect Worfed]] in favor of [=TaJaDor=] as Eiji and Ankh battle the BigBad [[FridgeBrilliance as one being]].]]
*** There are three possible reasons for this. One, [[spoiler:[=PuToTyra=] is the same "type" as Maki, so it probably wasn't as effective as against the desire-based Greeed]]. Two, [[spoiler:a true collaboration between Eiji and Ankh is what the series has been building up to]]. Three, [[spoiler: with [=PuToTyra=] out of the list, [=TaJaDor=] ''is'' the strongest form OOO has, as well as the ''only'' form available at the point]].
*** Looks like Toei decided to take the initiative here, by churning out '''[[CanonImmigrant Super TaToBa Form]]''' for ''Movie Wars Megamax''. It does reuse [=TaJaDor's=] head though.
*** Remember how Dr Maki turned out to be a fan of Music/BobMarley? [[spoiler:And [=TaJaDor=] form is literally made up of ''[[WaxingLyrical three little birds...]]'']]
** The PV for the OP [[http://www.youtube.com/watch?v=eYjFbRkPziU "Anything Goes"]] may have predicted key points of the finale. [[spoiler:Uva appears in it, and he's the last of the original Greeed to die. And the singer's name is ''[[NamesTheSame Maki]]'' Ohguro.]]
** Gara's OneWingedAngel form in ''Shogun and the 21 Core Medals'' is looking very [[VideoGame/TheElderScrollsVSkyrim Dovah-like.]]
** What was the first ever costume theme at the Cous Coussier? [[Series/KaizokuSentaiGokaiger Pirates.]]
*** Similarly, Hina asks Eiji what he always wanted to be in #35. His first choice? [[Series/KamenRiderFourze Astronaut.]]
** The BigBad's motivation is [[spoiler:to destroy everything before their "beauty" gets corrupted]]. Now, are we talking about OOO's main villain or VideoGame/PokemonXAndY's big bad?
** TheMovie's much-touted appearance of Tokugawa Yoshimune from ''Abarenbou Shogun'' has him reusing his old incognito name, Tokuda Shinnosuke. [[Series/KamenRiderDrive Now we have a proper Rider by that name!]]
* JerkassWoobie: In #29, when Kazari uses Maki to make a Yummy, it's revealed that his greatest desire is for [[spoiler: a hug]]. Though its pretty much subverted when we find out [[spoiler:he's the one who killed his sister because she was getting married and wanted to abandon him. When he remembers this, he doesn't seem all that guilty about it.]]
** FridgeBrilliance: It's no accident that the Yummy created from him [[spoiler: hugs women to death. It isn't a case of DoesNotKnowHisOwnStrength on the Yummy's part. It's his desire that if someone shows kindness and compassion, they should die before they can be corrupted by the world and taken from him like he felt his sister was.]]
* MagnificentBastard: Kougami; crazy as he is, makes it abundantly clear that he's in control of the situation in #6, forcing Ankh to accept a crooked deal in order for him and Eiji to use the [=RideVendors=] located around the city.
** Ankh himself isn't too shabby either: In #20, it is revealed that he [[spoiler: switched the core medals with cell medals in the case beforehand so that Kazari's apparent victory by stealing it in #19 was foiled.]]
** Kazari shows signs of this as well.
* MemeticBadass: Kougami the [[http://aesirsubs.wordpress.com/articles/cakeboss-archive/ Cakeboss]].
* MemeticMolester: King OOO. Why, fandom. Why.
* MoralEventHorizon: Kazari [[spoiler:using Gamel and Mezool in an experiment that could quite obviously be fatal and not caring one bit both were killed in the result. In fact, he ''smiles'' while he observes his handywork.]]
** If he didn't cross it by locking his assistants in a lab with rampaging Yummy ForScience, Dr. Maki crossed this when he realizes [[spoiler:he murdered his own sister and reacts, not with remorse, but by deciding he did the right thing by killing her and now it's time to destroy the world.]] It's more likely the latter, as before that point, he wasn't beyond redemption. It's this point that it becomes clear he's irredeemable. Made even worse by [[spoiler: the tensing of a HeelFaceTurn directly before it.]]
** [[spoiler:Eiji's father]] crossed this by [[spoiler:exploiting the fact his son was badly wounded and ''emotionally scarred for life'' by a war his family's money funded ''to get votes!'' How could anyone blame Eiji for walking out on his family after that?]]
* {{Narm}}: The upcoming summer movie involves some TimeTravel, and the design of medieval knights seen in the trailers [[Film/MontyPythonAndTheHolyGrail may look familiar to some viewers]]. [[ShoutOut Think they'll run away upon seeing the Greeed or OOO?]]
** Eiji and Ankh's confrontation in #46 is very heart-felt and serious, but all of that goes out the window when you suddenly realize that [[spoiler:[[http://tinypic.com/r/s6t2lv/7 Ankh's arm is being held together by scotch tape...]]]]
** And then there is [[LargeHam Kousei Kougami]] at episode 47 who overacted regarding about the purple core medals stuffs blocking the way.
* NightmareFuel: [[NightmareFuel/KamenRiderOOO Has its own page]].
* RetroactiveRecognition: Karin Ogino, Belle from [[TheMovie Shogun and the 21 Core medals]], has not only gotten a leading role in Series/HikoninSentaiAkibaranger, but a role in the upcoming ''Anime/TigerAndBunny'' [[LiveActionAdaptation stage show.]] Not bad for an AdvertisedExtra.
* TheyWastedAPerfectlyGoodPlot: In Series/KamenRiderDouble, a representative of Foundation X discusses the possibility of the Core Medals. In Kamen Rider OOO, Foundation X is never mentioned.
** However, they are now confirmed to appear in Movie Wars Megamax.
** On another topic, OOO's chestplate has been damaged so badly, the Tora TronLines were greyed out. It could have been in more scenarios where OOO is in a pinch.
** It would have been cool to see Giga Scan combos with other core medals. (In the entire series, only Batta and the Red and Purple ones have been used)
** The "Multi-King" form that the [[spoiler:Original OOO]], Kougami, and the Greeeds try to achieve. Considering how powerful individual combos are (and that [[spoiler:Greed!Maki]] got [[OneHitKill One-Hit Killed]] by just both [=PuToTyra=] and [=TaJaDor=], respectively), it would've been interesting to see the level of power that form would give out.
* ViewerGenderConfusion: Gara has a female live actor and a male voice actor, so this becomes inevitable. Justified, as Gara [[spoiler:possesses a woman]].
* SugarWiki/VisualEffectsOfAwesome: The last stage of the FinalBattle is done amazingly well, especially [[spoiler:when they fly inside of the Medal Vessel for the final exchange.]] They really outdid themselves on this one!
* TheWoobie: If you didn't feel sorry for Gamel while he was wandering around searching for Mezool like a lost puppy, you don't have a heart.
** Gamel again in #45 [[spoiler: where he's utterly heartbroken by Mezool discarding him once she's fully restored, and eventually ends up with her [[DiedInYourArmsTonight dying in his arms]]]].
** And again with Gamel in the next episode [[spoiler: as he dies and tries to give Mezool's last Core Medal a lollipop and hallucinates Mezool accepting the sweet before collapsing into a pile of Medals himself]].