Kamen Rider OOO (仮面ライダーオーズ／ＯＯＯ Kamen Raidā Ōzu) 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 GoseigerImage:Icon-crosswiki.png and then Kaizoku Sentai GokaigerImage:Icon-crosswiki.png 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. The catchphrase for the series is "I'll transform!!!" (俺が変身する!!! Ore ga henshin suru!!!).