Jubei-Chan: The Secret Of The Lovely Eyepatch

Three centuries ago, Yagyu Jubei, the greatest swordsman in Japan, all but destroyed a rival ninja clan. They have since lived in secret, plotting their revenge on all of Japan. Jubei foresaw this, and before he died, he created the Lovely Eyepatch that will bestow his swordsmanship mastery to his one chosen successor. Jubei's loyal servant Koinsuke is tasked to search this chosen one. Fast forward to present day, Koinsuke comes across an average high school girl named Nanohana Jiyu (nicknamed Jubei by her single father). Convinced that she is the true successor he has been looking for, Koinsuke gives the eyepatch to young Jubei, transforming her into the modern-day incarnation of the master swordsman, and an array of villains will put her skills to the test.