Kamen Rider OOO - Wikipedia

The Kamen Rider OOO trademark was registered by Toei on April 8, 2010.[2][3][4]

OOO is written by Yasuko Kobayashi, known for the screenplays of Seijuu Sentai Gingaman, Mirai Sentai Timeranger, Kamen Rider Ryuki, Den-O, and Samurai Sentai Shinkenger. The creature designers are Yutaka Izubuchi, known for his work on the Lords in Kamen Rider Agito, and Tamotsu Shinohara, known for his work on the Mirror Monsters of Ryuki, the Orphnoch of Kamen Rider 555, and the Fangires of Kamen Rider Kiva.[1]

Unlike several previous Heisei Rider Series, no alternate name has been given yet for the three O's in the title (Ｗ（ダブル） read as "Double" and 555（ファイズ） read as "Φ's/Phi's/Faiz") aside from an alternate spelling of the name of the main Kamen Rider: Ooz.[5] Both "OOO" and "Ooz" are intended to be read as "O's", referring to the multiple uses of the letter O in the title as well as "multiple kings" (王ｓ, Ōzu). The title OOO signifies the three medals that the main Kamen Rider uses to transform as well as being representative of the infinity symbol ( ∞ {\displaystyle \infty }  ) with an additional circle.

The 28th episode of Kamen Rider OOO serves as the 1000th episode of the Kamen Rider Series since Kamen Rider premiered on April 3, 1971. The episode was originally set to premiere on March 27, 2011. However, due to the 2011 Tōhoku earthquake and tsunami, the airing of this episode was postponed by one week to April 3, 2011. For the 999th and 1000th episodes, various guest stars with the kanji for thousand (千, chi) in their name were featured: Chiaki, Chisato Morishita, Chinatsu Wakatsuki, and the owarai duo Harisenbon (sen also being Japanese for 1000).[6]