Nobunaga no Shinobi
Chidori is a little ninja girl living in Japan's Warring States Period. One day, Oda Nobunaga rescued her from drowning in a river. Since that day, Chidori knew she wanted to serve Nobunaga. Five years later, she and Sukezou (who likes her) head out from their ninja village, determined to serve Oda Nobunaga!
(Summaries provided by MyAnimeList.net)