In a magical world where humans, demihumans, and oni are locked in a fierce conflict, Princess Saltorine "Sally" Aldike sets out on a journey to find Mikoto Kibitsu. Along the way, Sally uncovers hidden truths about the world and her own lineage, including the immense power of the oni that could potentially destroy humanity.
Gifted with a mysterious peach-shaped mark that gives her extraordinary abilities, Sally can easily overpower even the strongest oni. Still, she tries to remain neutral toward humans, demihumans, and oni, holding onto the belief that peace among these groups is possible.
Mikoto, who also wields the peach-shaped power but with greater control, has a very different goal. Determined to eliminate every oni, Mikoto stops at nothing to carry out this mission. As their paths cross repeatedly, the fate of peaceful coexistence or total destruction rests on the power that both Sally and Mikoto possess.