The protagonist of this story is Koto Nakazawa, a female swordsman who dresses as a man. She actually lived in the late Edo period (mid-19th century).

She is now training diligently in swordsmanship at her father and master Magoemon's dojo. Although her skills have already surpassed those of her father, she is not recognized as a samurai by society simply because she is a woman — a fact she laments.

Then, her brother Sadamasa rushes in with urgent news: a political upheaval has erupted, threatening the survival of the Tokugawa shogunate.

She is the female samurai who leaves her mark on turbulent history.
Now, from this dojo, she takes her first step into a new life!