The Fourth

Kuro Yamidara, a girl from the secret moon village hidden in the sky, travels by foot to the Village Hidden In The Leaves in search of a new sensei to teach her Jutsu's of all types. She used to have two other senseis but one had vanished and the other lied dead. She meets two boys Hachiro and Kitani, who were from her village searching for a new sensei to guide them. The three join a familiar group but she's the fourth member, hence the title name.