Junko Fukushima had been living as a sex slave to her husband when her teenage son accidentally discovered her in that humiliating state. Seeing his mother in such an unnatural position aroused him, and he proceeded to rape her. From that day on, her life split in two: by day, she became her son's slave; by night, she remained her husband's. Dominated by these two men in her everyday life, she gradually begins to recognize her own feelings and circumstances. Amid this complex relationship, she slowly starts questioning how she should truly live her life.