When a strange samurai tells her she is the successor of the swordsman Yagyu Jubei, Jiyu Nanohana refuses to believe him. But the descendants of Jubei's rivals have already sensed this, and one assassin after another is sent to attack Jiyu! Fortunately, Jubei left a little something for our heroine - a lovely heart-shaped eyepatch. As soon as Jiyu dons the eyepatch, she is overcome with Jubei's power and transforms into a ninja girl! Jiyu must put an end to the 300-year old feud between the samurai clans... before the feud puts an end to her.