For 500 years, a giant snake god has lived in the ancient mountain. Miyo, an unlucky young woman from the nearby village, has been offered as a tribute: she is to be the snake's bride.
Subaru Sumeragi is the thirteenth head of his clan and a powerful onmyouji. With the help of his twin sister Hokuto and the veterinarian Seishiro, he solves supernatural troubles in Tokyo and helps whomever he can.