History Series / KamenRiderOOO

** Date arriving [[spoiler:just when OOO and Ankh were about to be defeated by the two Beetle Yummies]] in #17. His entry is even more dramatic due to him doing a solo PowerWalk and then finally revealing his transformation sequence.

[[header:[[center:[-'''''Franchise/KamenRider'' -- Phase 2 Heisei Era'''\\
''[[Series/KamenRiderDouble Double]]'' | '''OOO''' | ''[[Series/KamenRiderFourze Fourze]]'' | ''[[Series/KamenRiderWizard Wizard]]'' | ''[[Series/KamenRiderGaim Gaim]]'' | ''[[Series/KamenRiderDrive Drive]]'' | ''[[Series/KamenRiderGhost Ghost]]'' | ''[[Series/KamenRiderExAid Ex-Aid]]'' | ''[[Series/KamenRiderBuild Build]]'' | ''[[Series/KamenRiderZiO Zi-O]]''\\
'''[[Series/KamenRiderDecade <<< Phase 1 Heisei Era]] | [[Series/KamenRiderZeroOne Reiwa Era >>>]]'''-]]]]]

* BigBad: The Greeed play this role for the series. [[spoiler:But [[OneWingedAngel the human turned Greeed]] Dr. Maki eventually took over this role.]]

* SurprisinglyGoodEnglish: The opening theme's English is, while odd, not incorrect.

* FemaleGaze: #1 has several minutes where Eiji is in nothing but boxers, and right after the first commercial we get a close-up of his butt. People into this all approve.

*** #27 has Akira take off his shirt in order to help an injured colleague, which proved to be a pleasant surprise to some.

* {{Foreshadowing}}: If you look on TV Asahi's website, you can see purple O Medals in the background... In the series, Dr. Maki gave it away in #29 by using the Pteranodon Candroid.

* FourIsDeath: There are four villainous Greeeds. [[spoiler:Ankh was against his own fellow Greeed 800 years ago.]]

* FusionDance: In #16 [[spoiler:Gamel and Mezool become one entity for a while.]]

* GratuitousEnglish: Kougami singing "HappyBirthdayToYou" in English while making a birthday cake for the Greeed and OOO. He also says "Doctor Maki" instead of "Maki-sensei" or "-hakase" or something.

* AmbitionIsEvil: Subverting this trope is the CentralTheme of the series. At first, it looks like the show is going to play it straight: the villains are literally called the Greeed and are motivated by such, while TheHero has no ambition whatsoever. There is however, Kougami, a character who extols the virtue of desire while supporting the hero; early in the series, his motives are shrouded in mystery. Eventually, it's revealed that Eiji's lack of ambition isn't what makes him a hero; it's what's ''holding him back'' from being an even better hero than he already is, and rather than giving Kougami a nefarious hidden agenda, the show firmly establishes him as the BigGood. Ultimately, the series ends up hammering home the point that a total of ambition is a form of depression, and depression is ''bad''.

* ArcNumber: "40" in the anniversary movie, though "3" in the main series.

*** '''Electric Eel/''Denki Unagi:''''' [[ShockAndAwe Electric]] [[WhipItGood whips]].

** '''Dinosaurs''': [[PteroSoarer Pteranodon]], Triceratops, ''Tyrannosaurus rex''. [[OurMonstersAreDifferent Other mythological creatures]] also fall into this category.

%%** [[AnAxeToGrind Axe]] [[SwissArmyWeapon Grinding]] [[HandCannon Cannon]]: Medagabryu[[note]]Primarily used by Putotyra Combo, although the other Combo forms can summon and use this weapon through the power of the purple Core Medals in Eiji's body. However, Putotyra is the only form that can control its Bazooka Mode. #45 reveals that when used by a different Combo, the Medagabryu can execute [[KillItWithIce ice-powered slashes]].[[/note]]

* WeaponOfChoice: The Medajalibur; a [[CoolSword sword]] created by Kogami Foundation, it can be used in or out of any form, it can be fueled by up to three Cell Medals, and can even execute a Scanning Charge. Basically a Cell-based artificial Scanning Charge, as opposed to OOO's natural Core-based ones.
** AnatomyArsenal: The Core Medals. See ComboPlatterPowers for each Medal's individual powers.
*** WeaponizedHeadgear: Head Medals provide Eiji's head with different powers.
*** DualWielding: Arm Medals equip Eiji's arms with a different pair of weapons.
*** ArmedLegs: Leg Medals augment Eiji's legs for different strategies. Of course, that's not to say they can't be used for combat.
** [[{{Fireballs}} Fireball]] [[FireBreathingWeapon Breathing]] [[LuckilyMyShieldWillProtectMe Shield]]: Taja Spinner, used by Tajadol Combo or any form that uses the Peacock Medal.
** [[AnAxeToGrind Axe]] [[SwissArmyWeapon Grinding]] [[HandCannon Cannon]]: Medagabryu[[note]]Primarily used by Putotyra Combo, although the other Combo forms can summon and use this weapon through the power of the purple Core Medals in Eiji's body. However, Putotyra is the only form that can control its Bazooka Mode. #45 reveals that when used by a different Combo, the Medagabryu can execute [[KillItWithIce ice-powered slashes]].[[/note]]
*** Which leads to DualWielding on occasion when used with the Medajalibur.
** MusicalAssassin: Burahngi, used by Burakawani Combo.

** '''Dinosaurs''': [[PteroSoarer Pteranodon]], [[StockDinosaurs Triceratops]], ''Tyrannosaurus rex''. [[OurMonstersAreDifferent Other mythological creatures]] also fall into this category.

** '''Reptiles''': Cobra, [[TurtlePower Turtle]], [[NeverSmileAtACrocodile Alligator]].

** Taken to UpToEleven levels in #32:

*** Each of his main forms also has one, each of them named to sound exactly like the Combos they're themed for: "Regret Nothing-Tighten Up" for Tatoba and all Random Combos, "Ride On Right Time" for Latorartar, "Got To Keep It Real" for Gatakiriba, "Sun Goes Up" for Sagohzo, "Time Juged All" for Tajadol [[spoiler:sharing with Ankh]], "Shout Out" for Shauta, and finally "Power To Tearer" for Putotyra. Taken UpToEleven with the [[AllYourPowersCombined the Combo Change Medley]], incorporating every theme into a single song.

** According to Kougami, OOO is written as the infinity symbol with an extra 'O' in front. The implications is that OOO's power is [[UpToEleven a step beyond infinity.]]

* SoundtrackDissonance: While the Greeed were massacring Kougami Foundation's motorcycle brigade, Kougami was singing along to ''an operatic adaptation of HappyBirthdayToYou.'' Seriously, the opening scene's level of disturbing was brought [[UpToEleven up to eleven]] because of this.

* IHaveTheHighGround: Ankh. Given that he represents the Bird Medals, it make sense.

* FiveManBand: From #37-42:
** BigBad: Kazari
** TheDragon: [[spoiler:Lost Ankh]]
** EvilGenius: Doctor Maki
** TheBrute: [[spoiler:Gamel]]
** DarkChick: [[spoiler:Mezool]]
** SixthRanger [[spoiler:[[SixthRangerTraitor Traitor]]: Date]]

* ''Kamen Rider OOO Hyper Battle DVD: Quiz, Dance, and Takagaruba!?'', a ''Televi-Kun'' magazine exclusive DVD.

** ''Kamen Rider OOO the Net Edition: Core Medal of Resurrection Prologue'' and ''Birth X is Born Prologue'', two ''OOO 10th'' prequel episodes released through the Toei Tokusatsu Fan Club.

Voted #3 series in the Heisei era and #3 product overall in NHK’s All Kamen Rider Popularity Vote.

* ''[[VideoGame/KamenRiderMemoryOfHeroez KAMEN RIDER: memory of heroez]]'': A video game crossing over with ''Double'' again, featuring the protagonist of ''Series/KamenRiderZeroOne''.

Kamen Rider OOO's airing also coincided with the [[MilestoneCelebration 40th anniversary]] of the franchise. So, even though he was never promoted as an anniversary Rider, OOO ended up headlining a commemorative 1000th episode of the Kamen Rider series and even the ''OOO, Den-O, All Riders: Let's Go Kamen Rider'' movie, where the [[Series/KamenRiderDenO DenLiner]] crew and even [[Series/KamenRider Rider 1 and 2]] also receive a fair amount of focus, but the story was generally told from the OOO cast's point of view.

** ''Kamen Rider OOO the Net Edition: Core Medal of Resurrection Prologue'' and ''Birth X is Born Prologue'', two '''OOO 10th'' prequel episodes released through the Toei Tokusatsu Fan Club.

* {{Deconstruction}}: The 10th anniversary movie deconstructs [[spoiler: SacrificialRevivalSpell. Eiji was successful in reviving Ankh, but ''he had to die in order to do so''. While the first half of the movie focused on defeating [[GreaterScopeVillain Ancient OOOs]], the other half shows what the consequences Eiji's death had to the main cast and how they needed to cope with it. And because desires won't vanish even if someone dies, the Kougami Foundation decided to ''[[NiceJobBreakingItHero create an artificial Greeed that fittingly becomes the]]'' '' FinalBoss.'' ]]

* {{Deconstruction}}: The 10th anniversary movie deconstructs [[spoiler: EquivalentExchange, and to an extent, HeroicSacrifice. Eiji was successful in reviving Ankh, but ''he had to die in order to do so''. While the first half of the movie focused on defeating [[GreaterScopeVillain Ancient OOOs]], the other half shows what the consequences Eiji's death had to the main cast and how they needed to cope with it. And because desires won't vanish even if someone dies, the Kougami Foundation decided to ''[[NiceJobBreakingItHero create an artificial Greeed that fittingly becomes the]]'' '' FinalBoss.'' ]]

* ''KamenRiderOOO10thCoreMedalOfResurrection'', a movie that's set over 10 years after ''OOO'' ended that was released in Spring 2022.

* ''Kamen Rider OOO 10th: Core Medal of Resurrection'', a movie that's set over 10 years after ''OOO'' ended, which is scheduled to be released in Spring 2022.

* {{Deconstruction}}: The 10th anniversary movie deconstructs [[spoiler: EquivalentExchange, and to an extent, HeroicSacrifice. Eiji was successful in reviving Ankh, but ''he had to die in order to do so''. While the first half of the movie focused on defeating [[GreaterScopeVillain Ancient OOOs]], the other part shows what the consequences Eiji's death had to the main cast and how they needed to cope with it. And because desires won't vanish even if someone dies, the Kougami Foundation decided to ''[[NiceJobBreakingItHero create an artificial Greeed that fittingly becomes the]]'' '' FinalBoss.'' ]]

* {{Deconstruction}}: The 10th anniversary movie deconstructs [[spoiler: EquivalentExchange, and to an extent HeroicSacrifice. Eiji was successful in reviving Ankh, but ''he had to die in order to do so''. While the first half of the movie focused on defeating [[GreaterScopeVillain Ancient OOOs]], the other part shows what the consequences Eiji's death had ''to the main cast'' and how they needed to cope with it. And because desires won't vanish even if someone dies, the Kougami Foundation decided to ''[[NiceJobBreakingItHero create an artificial Greeed that fittingly becomes the]]'' FinalBoss.]]

** ''Core Medal of Resurrection'' manages to top this off even further. [[spoiler:Ankh wakes up to find himself in a war-torn world torn apart by the revived king OOO, and, to top it all off, Eiji is ''dead'', with Ankh's revival having happened as a result of Eiji's dying wish. But Eiji is perfectly satisfied and at complete peace, because he'd finally been able to clear his regrets and achieve his greatest wishes in [[MyGreatestSecondChance saving a young girl in the same way he couldn't in the past]] and allowing Ankh to live. Ultimately, after years of WalkingTheEarth trying to make up for his past failure and searching for a way to restore Ankh, the two are finally able to briefly meet again, Ankh fulfills his request to fight together and protect everyone [[TheLastDance one last time]], and Eiji dies [[ThanatosGambit knowing exactly what he wanted]], [[GoOutWithASmile having accomplished it the way he wanted]], and surrounded by his friends.]]