Itachi Uchiha is a former ninja of Konohagakure and the partner of Kisame Hoshigaki. Though having spent his early youth as the child prodigy of the Uchiha clan, Itachi is treated as a villain for much of the series. He is initially portrayed as being solely responsible for the killing of his entire clan and family, sparing only his brother, Sasuke Uchiha, with the explanation that he was testing his abilities.
