2009
- Decade visits the World of Kuuga. (Ep. 2-3)
- Decade visits the World of Kiva. (Ep. 4-5)
- Decade visits the World of Ryuki. (Ep. 6-7)
- Decade visits the World of Blade. (Ep. 8-9)
- Decade visits the World of Faiz. (Ep. 10-11)
- Decade visits the World of Agito. (Ep. 12-13)
- Decade visits the World of Den-O. (Ep. 14-15)
- Decade visits the World of Kabuto. (Ep. 16-17)
- Decade visits the World of Hibiki. (Ep. 18-19)
- Decade visits the World of Negatives. (Ep. 20-21)
- Decade visits the World of Diend. (Ep. 22-23)
- Decade visits the World of Shinkenger. (Ep. 24-25)
- Decade visits the World of Black RX. (Ep. 26-27)
- Decade visits the World of Stronger, and battles both the original Stronger, coping with the apparent Bus Crash of Tackle across The Multiverse, and this world's Stronger, who was driven insane by his Delza's lack of a leader only to become the leader himself. (World of Stronger)
- Decade visits the World of Amazon. (Ep. 28-29)
- Decade visits the World of TV Kun. (Protect! The World of Televi-Kun)
- Decade returns to the World of Decade, then fights with all the Riders against Dai-Shocker. (All Riders vs. Dai-Shocker)
- Decade visits the World of the Rider War. (Ep. 30-31)
Post-series
- Decade hunts down and destroys all the Kamen Riders, then allows himself to be slain by Kiva-la. As a result, the Kamen Rider multiverse is restored, with Decade himself returning thanks to his friends. Decade and his fellow Riders then fight against Super Shocker. (The Last Story) Teaming up with Kamen Rider Double, Decade defeats Ultimate D. (Movie War 2010)
- 2010: Diend returns to the World of Den-O. (Episode Yellow)
- April 2012: Decade returns to become the Great Leader of Dai-Shocker, whose goal is now to wipe out the heroic Super Sentai. To that end, they oppose Dai-Zangyack, led by Emperor Marvelous (Gokai Red), who seek to wipe out the Kamen Riders. The first Sentai to fall are the Gorangers, while Marvelous defeats the Seven Legendary Riders. (Super Hero Taisen)
- April 20th: Backed-up by Dai-Shocker's forces, Decade attacks the Tokumei Sentai Go-Busters before he is confronted by the other Gokaigers, seemingly killing Gokai Yellow, Pink and Silver.
- April 21st: Rider #1 leads the surviving Kamen Riders against the surviving Super Sentai led by Akaranger. When all the Riders and Sentai bar Rider #1 and Akaranger are wiped out, they reveal themselves to be Tsukasa and Marvelous in disguise respectively. At this point, Dai-Shocker and Dai-Zangyack usurp their respective leaders to form the Shocker-Zangyack Alliance, only to learn that the plan all along was for the Riders and Sentai to be assembled under the pretense of being defeated. Once the presumed deceased superheroes emerge through the dimensional rift, the combined Sentai and Riders defeat the Alliance's army of monsters.
- 2013
- Decade participates in the battle against Space Shocker. (Super Hero Taisen Z)
- 2014: Tsukasa is embroiled in the war between the Heisei Riders and the Showa Riders, and the battle against the Underground Empire Badan. (Kamen Rider Taisen)
- 2015:
- Tsukasa visits the World of OOO, while Natsumi ends up in the World of Gaim. Hijinks ensue when the Decade cast begins replacing main characters from both series and Narutaki resumes his more villainous activities, but the heroes manage to reunite and take him down. The Kamen Ride: OOO card and all of its associated cards are unsealed here. (World of OOO)
- Following suspicions that Kugai Kudo/Kamen Rider Saver may be manipulating the A.R. Worlds, Tsukasa locates the original Mitsuzane Kureshima (who was at the time trapped in a void by Kudo's powers) through the power of the Aurora Curtain and gives him a Rousing Speech. His intervention allows Kudo to be put down for good. (Novel: Kamen Rider Gaim)
- 2018-2019: Tsukasa visits the World of Zi-O in his attempt to change the fate of his successor Sougo Tokiwa into a proper hero instead of being the feared future tyrannical demon king.
