The film is set in Karafuto after the radio broadcast of the Imperial Rescript on the Termination of the War. On August 15, 1945, Soviet forces invaded Karafuto. On August 20, the postal telegraph office in Maoka suspended operations and nine of the twelve telephone operators committed suicide by taking potassium cyanide while the city was being invaded.

Terumi Niki
as Ritsuko Sekine

Keiko Torii
as Nobue Fujikura

Kawai Okada
as Natsuko Saito

Yumiko Fujita
as Ayako Sakamoto

Hiromi Kurita
as

Midori Kiuchi
as

Sanae Kitahara
as

Go Wakabayashi
as

Toshio Kurosawa
as

Yōko Minamida
as