Takehito Koyasu
On April 21, 1999, Geneon Entertainment released a drama CD titled . With music by Tomohiko Kira, it featured Hideo Ishikawa as Cain, Koyasu Takehito as Riff, Kawada Taeko as Mary Weather, Miki Shinichiro as Dr. Allen, and Jūrōta Kosugi as Alexis. The same company released a second drama CD, , on November 17, 1999. The drama CD featured Hideo Ishikawa, Kyoko Hikami, Takehito Koyasu, from "Kafuka" and included Taeko Kawada and Junko Asami.