Yōko Koizumi is a Japanese actress . Her alternate stage name is Nobiko Sawa. In 1974, she joined Toei Kyoto . In 1975, she played the role of a tragic heroine in "Gambling Den Heist". It was thought that she would retire when she got married, but in 1977 she changed her stage name to Nobiko Sawa and was active in Toei movies and dramas.