|This article is about a/an actor in Kamen Rider Build.|
Kenji Ohtsuki (大槻 ケンヂ Ōtsuki Kenji, born 大槻 賢二) is a Japanese rock musician, writer and actor. His musical career began in the late 1970s. He is also the founder and vocalist of rock band "Tokusatsu" and author of a 2006 novel Sewn Human Nuigulumar, which was adapted into a tokusatsu film named Nuigulumar Z in 2014.
He played Kaisei Mogami and Kaisei Mogami (World of Ex-Aid), the main antagonists of Kamen Rider Heisei Generations FINAL: Build & Ex-Aid with Legend Riders.