Kiyoto Maki is a major antagonist in the tokusatsu series Kamen Rider OOO. He is a scientist working for the Kougami Foundation and plays a crucial role in the creation of the Greeed, the main monsters of the series. Driven by nihilism and a fascination with endings, Maki becomes increasingly obsessed with bringing about destruction. His complex motivations and tragic past make him a compelling villain, and his actions significantly influence the series' main conflicts and the development of the protagonist, Eiji Hino.