With a large creature mysteriously attacking demons, Takatsuki is forced by her family to move in with Tomo so that he can protect her. At the same time Shuri arrives with a young demon named Ania, who Tomo also has to protect. However, Ania is a 'Luck-Eater' and causes misfortune to befall Tomo and his friends. Things get even more complicated when it turns out that Ania's sister, Kristina maybe involved with the demon hunts.