Excerpts from Godzilla Encyclopedia
Mysterious people who appeared in Ken’s dream. Hedorah ravishes the city and kills human health and lives. Godzilla appears and wipes it out !! But who gave birth to Hedorah?
Cosmic Black Hole Third Planet
Aiming to invade the earth based in Okinawa. He looks like a human, but he is a monkey. It was Daigo Kusano, a friend of Shin Kishida, who played Yanagawa, a senior soldier.
[Shin Kishida (17 October 1939 – 28 December 1982) was a Japanese television, film, and stage actor. He played the Interpol Agent Nanbara in Godzilla vs MechaGodzilla 1974. Source: Wikipedia]
[Daigo Kusano (September 7, 1939-February 27, 1991) is a Japanese actor. He is from Taichung City, Taiwan. Actress Kazuko Tajima is his wife. His character, Yanagawa, is a Third Planet from the Black Hole operative who attacked Dr Wagura and Keisuke to get the King Shisa statue.]
Source: ゴジラ大図鑑 東宝特撮映画の世界 Godzilla Encyclopedia: The World of Toho Special Effects Movies, pp 121, 137