Asao Koike was a Japanese actor and voice actor, active from the 1950s until the mid-1980s. He was born in Tokyo on March 18, 1931, and passed away on March 23, 1985. His career began on the stage when he joined the Bungakuza theatre company in the 1950s. He later became a founding member of the Gekidan Kumo theatre company and was also a core member of Gekidan Subaru. While he was primarily known for his extensive work in film, particularly in yakuza genres and period dramas, he also contributed his voice to a number of animated works. On screen, he was a frequent collaborator with directors like Kinji Fukasaku and actors such as Bunta Sugawara, appearing in numerous films of the era.

In the realm of anime, Koike's voice acting roles were primarily in feature films during the late 1960s and early 1980s. His most notable roles include providing the voice for the character Kamarkim in the 1969 film A Thousand & One Nights. He also voiced the character Silver in the 1971 film Animal Treasure Island. One of his later and more prominent voice roles was as the villain Rotbarth in the 1981 film Swan Lake. These performances demonstrate his contribution to the golden age of Japanese theatrical anime, bringing a range of characters to life with his distinctive voice.