Akiko
The wife of Shigemaru and a supposed beauty. Shigemaru fell madly in love with her, forcing him to obey her every will. They met when Shigemaru went hunting and happened to see them. Spoiler She was originally another man's wife but Shigemaru craved for her and ended up killing Akiko's helper and husband. Upon returning to his house, he carried her because she threatened she won't be her wife if he did otherwise. She ordered Shigemaru to kill his ex-wives or else she won't be his wife. So he killed every one of them except for the youngest which she also ordered to spare. When they finally moved to the city, she got bored and told Shigemaru to bring something fun home. Shigemaru beheaded the people she would request for i.e. priest, shrine maiden etc. Every night she would play with these heads with glee. In the end, Shigemaru realized that she was a demon.