As the daughter of a long line of priests, Rina Oikawa was also helping her family today by working as a shrine maiden. Her everyday life was following the same peaceful routine. However, the sudden appearance of the demonic Ioni would change her life forever. She couldn't just let those devils run loose and hurt people. She resolved to fight, not for her own sake but as an ally of justice, as the Shrine Maiden. But many times she would be overwhelmed...