Jiyu Nanohana lives as a typical high‑school student until she encounters an absent‑minded samurai who, after three centuries of wandering, declares that she is the reborn spirit of Yagyu Jubei. By donning the "Lovely Eyepatch," she morphs into the famed swordsman whenever her extraordinary combat skill is required, a necessity that recurs often as an opposing clan relentlessly pursues the Yagyu legacy to settle an ancient everlasting that has haunted for generations.