Kōichi Yamadera
is a 2006 Japanese science-fiction psychological thriller anime film co-written and directed by Satoshi Kon, based on Yasutaka Tsutsui's 1993 novel of the same name, about a research psychologist who uses a device that permits therapists to help patients by entering their dreams. It is Kon's fourth and final feature film before his death in 2010. The film stars the voices of Megumi Hayashibara, Tōru Emori, Katsunosuke Hori, Tōru Furuya, Akio Ōtsuka, Kōichi Yamadera, and Hideyuki Tanaka.