Yasuzou Muramatsu was an Ookawa's employee and Yasuyo's father. Ookawa alsways called him "Matsu". He calls Ookawa and mentions that Yasuyo died. During the war, he was bitten by Yoshie Kurahashi, who gave him with a gun, and ordered to shoot and kill Toshio Ozaki. However, he shoots and kills Atsuko Yasumori instead. He is then killed by Ookawa.