Asahi Nazuki, an ordinary office worker in modern Japan, loses consciousness in a traffic accident and awakens in a samurai estate during Japan's Warring States period. She is taken as a 'concubine candidate' by Himura Yoshimasa, a ruthless warlord feared as a man without a human heart. Yoshimasa is known as a 'demon,' and his existing concubines live in fear of his cold gaze. Yet Nazuki, with her modern naivety, speaks to him, smiles at him, and sometimes defies him. Gradually, she discovers t