Natsumi Hikari is haunted by a dream in which an army of Kamen Riders is engaged against an unknown enemy who wipes them all out. At the end of the dream she identifies the unknown enemy as Decade. She awakes from the dream, and has to deal with the trouble that the amnesiac Tsukasa Kadoya has gotten himself in yet again due to his uniquely terrible photographs. Then, the world all around them falls apart as monsters from past Kamen Rider shows arrive and wreak havoc. When all seems lost, a vision guides Natsumi to the lost DecaDriver which she delivers to Tsukasa, allowing him to transform into Kamen Rider Decade and fight off the enemies besieging them; however, no one man could fight off that many enemies, and so Wataru Kurenai, Kamen Rider Kiva, appears to them and explains that the stories of the Kamen Rider Worlds have become connected and thus the worlds are becoming one, and if not stopped all will be lost. Charging Decade with traveling to 9 worlds and killing the Riders of those worlds, Wataru returns them to the Hikari Photo Studio, and so begins the journey through the decade.
To start off, I freaking love meta stories, stories that are about stories are my favorite, narratives picking themselves apart to go into the nuts and bolts of the tropes that define those narratives, commentating on past stories, finding the thematic connections and logic between them…what I’m saying is that a Kamen Rider having to travel through Alternate Universe versions of past Rider shows and having to learn from them is something that was practically made for me.
Unfortunately, the reality is not so rosy; on an individual level any given arc of Decade is fine, none of them being especially bad and some of them even being better than I would have expected given the source material, but as a whole the show simply doesn’t work. Decade is an incredibly high-concept show, one that demands a plan, a well-plotted progression that will express whatever message the show is meant to convey. Decade does not have that. There is no progression, there is no focus, and there is no explanation about hardly anything, it’s just Decade and company wandering from one set-piece to the next, saying there bits and doing their things to shill out the toys related to that world. It doesn’t get really bad until the end of the series, which just suddenly ends with trailers appearing proclaiming that the upcoming movie would answer everyone’s questions…only that movie ended up going through so many revisions that not only did it not answer anyone’s questions, but in fact became incompatible with how the show ended, necessitating re-edited versions of the last two episodes so that things would be marginally more in line with how the last movie handled things.
That, is a special kind of failure to plan things out.
Decade is not a blight on the Kamen Rider franchise, individual pieces of it can be enjoyed, but this is a show that falls far below the potential it could have achieved.