Kōichi Yamadera
is a Japanese actor, voice actor and narrator. He is employed by the talent management firm 81 Produce. When he debuted, he used his real name, . as artist name. Because he had experience with ballet, he was known by the nickname "Pirouette Genda." Along with such well-known voice actors such as Akio Ōtsuka, Shigeru Chiba and Kōichi Yamadera, Genda is one of Japan's most prolific voice actors, with 234 roles credited to his name as of September 25, 2007.