Long ago, in Japan, there existed demons of unparalleled beauty, gifted with extraordinary powers. Otoha Sakuraba, a novice Onmyoji, lost her mother to a red-haired demon boy when she was a child. The trauma left her with no memories of her life before the tragedy. Orphaned and alone, she was taken in by Touma Tsukikage, the Chief of the Onmyoji Bureau. Determined to repay his kindness and avenge her mother, Otoha devotes herself to her duties. One day, while pursuing a suspected demon woman, she crosses paths with Homura — the enigmatic and striking leader of the demons. Bracing herself to face her mother’s murderer, Otoha is taken aback when Homura greets her with an unexpected gentleness. Why would the very demon she swore to destroy treat her with such tenderness? A Meiji-era romantic fantasy of demons and Onmyoji, where the boundaries between enemy and ally begin to blur.