Saltorine Aldike, or Sari, is a bright, cheerful princess who wants to go on an adventure because she is bored of her tiny little castle in the countryside. One day, a hoard of vicious demons known as "Oni" come knocking on her doorstep, threatening the lives of everyone in the Kingdom. Thankfully, they are saved by a lone traveler named Kibitsu Mikoto who slays these monsters with a mysterious "Peach Eye." Shocked by the dangers of the outside world, Sari decides to set off on a journey of her own. Little did she know that she would set in motion a chain of events that will come to determine the fate of this magical world.
A great war has raged for years between the scientifically advanced Empire and Nebulis, the realm of the witches―until the youngest knight ever to receive the title of the Empire's strongest meets the princess of the rival nation.
Though they are sworn enemies, the knight is taken by her beauty and dignity, and the princess is moved by his strength and way of life.
Will the fighting between them ever be allowed to end?