Kamen Rider OOO (仮面ライダー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 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. The series centers around medals, animals, and the themes of desire and greed. The series follows Eiji Hino, who becomes Kamen Rider OOO after obtaining the power of the Core Medals, which are linked to three different animal species (the Hawk, Tiger, Cheetah, Stag Beetle, and Grasshopper) and grant him the ability to transform and use various powers.