Kamen Sentai Gorider is a three episode Web Video Series that ties into Cho Super Hero Taisen.
Emu wakes up on top of a rollar coaster in the middle of an amusement park with no memory on how he got there. He meets up with five other riders who have previously died or went missing:
- Kaoru Kino/Another Agito:
- Kaito Kumon/Kamen Rider Baron and Yoko Minato/Kamen Rider Marika:
- Kazuma Kenzaki/Kamen Rider Blade:
- Kiriya Kujo/Kamen Rider Lazer: Emu's most familiar ally who previously succumbed to the Bugster Virus after losing to Kamen Rider Gemn.
They must figure out why they are here, all while something sinister is going on, as things are not what they seem to be...
- The Comically Serious: A good bit of humor in the special comes from the fact that the Gorider powers (which are deliberately goofy and firmly tongue-in-cheek) get handed to four serious characters from serious shows (and Kiriya). One wonders how much fun the actors had hamming it up and acting like 70s-era Toku characters.
- Couldn't Find a Pen: Emu finds a broken shard of mirror with a sequence of numbers written on it in blood. It turns out to be his own blood, written during a previous loop after Blade fatally stabbed him.
- Foreshadowing: The first episode leaves enough clues as to what's going on and the identity of the culprit.
- The numbers Emu finds in the house, Is actually code using Japanese Hifumi numbers: 2010 | 8 | 9609note = BLADE | IS | THE MASTERMIND.
- When they look at the mirror we see all but Emu have no reflection. Kenzaki should have a reflection because as the Navy Joker Undead, he's effectively immortal and can't die, not to mention the other bad things that would happen if he was dead.
- A memory shows Blade stabbing Emu, not only telling who isn't the real thing, but also foreshadowing the nature of the world.
- Didn't Think This Through: Kuroto's plan would've succeeded...if it wasn't for the fact that he chose the one "dead" rider that could actually thwart his plans. See Hoist by His Own Petard for more.
- "Groundhog Day" Loop: This series has a variation It's actually a game that Emu enters each time with his memory wiped, and the events go as usual till he beats it.
- Hoist by His Own Petard: Kuroto Dan, the main villain, does this to himself twice over. After he kills Emu while disguised as Kazuma Kenzaki, he can't resist the urge to engage in some Evil Gloating, revealing his identity to Emu and allowing him to leave a message to warn the others. However, the fact that he impersonated Kenzaki was his ultimate undoing: it drew the attention of the real Kenzaki, and once he entered the game world the rules of the Battle Fight came into effect. Since he's the last Undead left, he "wins" the Fight...but since he's the Joker, that means The End of the World as We Know It. Cue the game world crashing into the standard BBC Quarry and Kuroto's plans being completely thwarted.
- Laser-Guided Amnesia: Each time he enters the game, Emu's memory is erased.
- Missing Reflection: Emu meets several slain Kamen Riders in a Closed Circle mystery. The room where they spend most of their time has a giant mirror, and none of the dead Riders casts a reflection — but Emu does, which makes them suspicious. This actually gives away real culprit: one of the Riders present is Kazuma Kenzaki (Kamen Rider Blade), who didn't die at the end of his series but rather turned himself into a monster (though he initially claims that's the same thing as being dead). When the real Kenzaki shows up, he casts a reflection just like Emu, exposing the impostor.
- Unwinnable by Design: The mystery simulation in which Emu finds himself at the start of the special seems this way. Every time he loses, he's booted back out to the real world with no memory of what happened, meaning that every time he goes back in it's with a clean slate. Poppy even describes it as such, using the Japanese term "murige"note . It only becomes winnable because Kuroto's decision to pose as Kazuma Kenzaki attracted the real Kenzaki, and his entering the game world invoked the rules of the Battle Fight — and since the last Undead standing is the Joker, it's game over.
- What Happened to the Mouse?: We never learn what happens to the real Kenzaki after he and Emu escape from the world - presumably, he returned to the real world, since if he didn't, the Battle Fight would result in Chalice winning and wiping out all life on Earth.