Suddenly, the curse of the Amanojaku (perverted demon) makes a horn grow out of Ayaka, a twisted junior high school student. In order to remove this “horn that hurts when you say something different to your true feelings”, withthe help of Nayuta, a genuine Amanojaku she meets in 99's Village, she aims to become a good person. However, will she be left at the mercy of the beautiful demon girls!?