Saya is a second-year high school student at the private Sanjing Academy. Although she usually lives an ordinary school life with her classmates, she has to accept her father's order to complete a certain "mission". That is to hunt for things called "antiques", which have power far beyond that of humans and feed on humans. As the only one who can hit the "antiques", Saya fights alone with the divine sword passed down from the Ukishima Shrine in order to protect others and her beloved father.