Nine universes of the previous Kamen Riders from the Heisei era are merging into one, something that would destroy all the worlds. To prevent this, Tsukasa Kadoya transforms into Kamen Rider Decade and is told that to protect his own world he must travel to all of the other Kamen Riders' worlds (Another Rider's worlds) and eliminate the anomalies in those worlds. Along the way, confronting the mysterious Narutaki and the thief Daiki Kaito, they are joined by Yusuke Onodera of the World of Kuuga and Kivala of the World of Kiva.
Rider War
The World of Kuuga
Transcendence
Second Movement ♬ Kiva the Prince
Qualifications of the Biting King
Battle Trial: Ryuki World
The True Culprit's Super Trick
Welcome to Blade Cafeteria
Blade Blade
Phantom Thief of Faiz Academy
555 Faces, 1 Treasure
Reunion: Project Agito
Awaken: The Soul Tornado
Super Den-O Beginning
Here Comes Super Momotaros!
Warning: Kabuto is Out of Control
The Path of Grandmother's Flavor
Missing Hibiki
Journey's End
The Dark Riders of Nega World
Going Through the Complete Rider Album
Diend is Wanted
End of Diend
The Samurai Squadron Appears
Corrupt Rider, Go Forth!
RX! Great-Shocker Invasion
BLACK×BLACK RX
Amazon, Friend
The Strong Naked Strongman
Rider War: Prologue
The Destroyer of Worlds
Otherworld
Sliders
Space Sheriff Shaider
GoGo Sentai Boukenger
Choudenshi Bioman
Ultraman 80
Ultraman Ace
Stormworld
GARO
Mirai Sentai Timeranger
Ultraman
Ultraman Dyna
Ultraman Max
Space Sheriff Sharivan
Himitsu Sentai Gorenger
Taiyo Sentai Sun Vulcan
Ninpuu Sentai Hurricaneger
Police × Warrior Love Patrina !
Ultraman Trigger: New Generation Tiga
Kamen Rider Ryuki