During the early Heian period, Fujiwara no Yoshifusa and his adopted heir Mototsune maintained control over the Imperial Court. Mysterious incidents frequently occurred in ancient Kyoto where a procession of demons would strut through the streets monthly on the day of the Rat, killing anyone who saw them. By chance, Sugawara no Michizane becomes acquainted with Ariwara no Narihira, the head of the police and judicial chief. Recognizing Michizane’s talents, who from a young age was a brilliant and renowned scholar, Narihira asks for his help in solving the mystery. Thanks to the cooperation of Shoki, an obstinate female shopkeeper who deals in Tang Dynasty goods, Michizane gradually draws closer to solving the mystery. In the background, however, swirls the greed of secretive powerful figures who mask their intrigues as the deeds of demons and specters…