One day, the world was invaded by ‘demons’ that appeared from a gate. Humans, who made contracts with ‘divine spirits’, a race destroyed by the demons, became ‘hunters’ and gained supernatural powers, allowing humanity to begin fighting the demons.

Despite becoming a hunter, Asuka Makoto remained an outcast for two years as no divine spirit appeared to him. Then, a beautiful girl appeared before him seeking a contract, but she wasn’t a divine spirit- she was a demon…!?