During her senior year of middle school, Tera receives an invitation to attend a secret school specializing in training teenagers to hunt demons that cause sickness. The students gain supernatural strength by feeding on demon blood like vampires. Although she is disbelieving at first, Tera soon discovers that she fits in well at the school. Soon she goes as far as to have a popular boy named Ailen show interest in her. However, as Tera delves more deeply into Jubeni she discovers a sinister secret that holds the cause behind her dying sister's illness. Tera must choose between her desire for popularity at among her beloved new classmates and searching for the truth behind the mysterious institution.