Peach Boy Riverside

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.

(Source: Peach Boy Riverside Wiki)