Jiyu Nanohana is an ordinary schoolgirl until she runs across a scatterbrained 300 year old samurai who tells her that she is the reincarnation of Yagyu Jubei. With the help of the "Lovely Eyepatch" she transforms into the legendary swordsman whenever she needs to use his awesome fighting ability, which she needs to do quite often as a rival clan is dead set on conquering Yagyu to satisfy an old family grudge.

Season 2: The Counter Attack of Siberia Yagyu :

Three hundred years ago, in the frigid land of Siberia, Jubei Yagyu engaged in a fierce battle with Kitaretsusai of the Northern Yagyu clan. The duel was costly, as his daughter Freesia was frozen in suspended animation. As a result of global warming in the present day, Freesia breaks free from her icy grave and moves to Japan as a middle school transfer student, where she befriends Jiyuu Nanohana. Little does Jiyuu know that Freesia is targeting her to acquire the coveted Lovely Eye Patch, which Freesia believes is rightfully hers.