! All spoilers for ''Series/KamenRiderDecade'' will be unmarked ahead. Administrivia/YouHaveBeenWarned

The {{crossover}} between ''Series/KamenRiderW'' and ''Series/KamenRiderDecade''.

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! Tropes
* CerebusRetcon: [[spoiler:Natsumi going from tsundere comic relief to '''Tsukasa's killer''' in ''The Last Story''.]]
* ChekhovsGun: The photograph of Tsukasa that was taken by Natsumi near the beginning of ''The Last Story'', [[spoiler:which is what is used to revive Tsukasa for the final battle]].
* DefeatEqualsExplosion: Exaggerated, with not just monsters, but defeated Kamen Riders.
* EarlyBirdCameo: TheStinger features Ryu Terui, Kamen Rider Accel.
* FakeShemp: Among the Nine Worlds' Riders, the actor for Takumi Ogami (A.R. Faiz) could not be secured, so he is voiced by Kenji Akabane.
* TheRemnant: Super Shocker in ''The Last Story'', formed from the leftovers of Dai-Shocker's army.
* TheStinger: Ryu Terui arrives in Futo, observing that Double is not the only Rider in the city now as he produces his Accel Memory.
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