Each year, the villagers of a certain mountain village hold a festival to celebrate the harvest. Tominaga Yuuki, a 17-year-old born outside the village, is chosen to play the role of purifier in the Oni exorcism, the festival's most important ritual, opposite 3-year veteran of the dance Kurashina Hana, his female classmate. In the days leading up to the festival, Yuuki gets more and more fru strated with his role, until he starts to see...?