When he was reincarnated into a different world, he had turned into a woman. Furthermore, when her parents died in a disaster caused by a demon attack, an elderly man saved and brought her up. That man was a former knight of the Kingdom who was once renowned as Sword Saint.

Time passed, and a letter of summons from the Kingdom arrived for her Sword Saint Grandfather – who has retired deep in the countryside's mountains for some reason. She then went to the Royal Capital as a representative for her Grandfather who hurt his lower back, in order to pay back his kindness even a little.

This is a story of the strongest female swordsman, trained by the Sword Saint himself, as she goes on an adventure in an alternate world.