|This article is about a/an voice actor in Kamen Rider Zero-One.|
Kōichi Yamadera (山寺 宏一 Yamadera Kōichi) is a Japanese voice actor and singer who serves as the main narrator for Kamen Rider Zero-One.
As a voice actor, he is best known for his roles in several well-known anime such as Spike Spiegel in Cowboy Bebop, Beerus in Dragon Ball Super, Ryoji Kaji in Neon Genesis Evangelion, and the current voice of Koichi Zenigata in Lupin III. He was once married to voice actress Rie Tanaka from 2012 to 2018.
In tokusatsu, he had various roles in Ultraman and Super Sentai.