Kamen Rider OOO is a 2010–2011 Japanese tokusatsu drama in Toei Company's Kamen Rider Series, being the twelfth series in the Heisei period run and the twenty-first overall. It began airing on September 5, 2010, the week following the conclusion of Kamen Rider W, joining Tensou Sentai Goseiger and then Kaizoku Sentai Gokaiger in the Super Hero Time lineup, until its conclusion on August 28, 2011. The series' titular Kamen Rider made a cameo appearance in the film Kamen Rider W Forever: A to Z/The Gaia Memories of Fate and a supporting character in other Kamen Rider movies.

Kamen Rider W , also called Kamen Rider Double, is a 2009–2010 Japanese tokusatsu drama, the eleventh series in the Heisei period run of the Kamen Rider Series and the twentieth overall. It premiered following the finale of Kamen Rider Decade on September 6, 2009, and aired alongside Samurai Sentai Shinkenger in TV Asahi's Super Hero Time programming block. Following Shinkenger's finale, it aired alongside Tensou Sentai Goseiger, until W concluded on August 29, 2010. The series is described as the "Heisei Kamen Rider 10th Anniversary Project: Fall Campaign" . In the first episode of Kamen Rider Fourze, W is revealed to be in the same continuity as the original Showa timeline, making it the first series to do so since Kamen Rider Agito. The series is notable for being the first installment in what's popularly viewed as Heisei era Kamen Rider's second phase by fans. A sequel manga series, Fuuto PI, began serialization in August 2017 and an anime adaptation began airing in August 2022.