Itachi Uchiha(うちは イタチ,Uchiha Itachi) is a missing-nin from Konohagakure and is partnered with Kisame Hoshigaki. During his time in Konoha, Itachi's prodigious talents and rapid development into a skilled ninja earned great attention from his family, the Uchiha clan. His skills were such that his family focused all of its attention on him and the prospect that he would be the clan's future, ignoring Itachi's younger brother, Sasuke Uchiha, in the process. Over time Itachi began to distance himself from the village and his family, eventually becoming a prime suspect in his best friend, Shisui Uchiha's, death. Before the death could be properly investigated, Itachi killed all the members of the Uchiha clan in a single night so that he could "test [his] ability". Itachi decided to spare Sasuke, however, feeling he was not worth killing; instead, prior to leaving, Itachi told Sasuke to live hating him and get strong enough to avenge the clan. At some point in time Itachi joined Akatsuki. While it stands to reason that he joined after massacring the Uchiha clan, the timeline that has been given throughout the series coupled with his age suggests that he joined the organization prior to killing his clan. Although he talks with Kisame many times and even smiles, he never talks to other Akatsuki members unless he is ordered to. Despite his status as a wanted criminal and murderer, Itachi does not display any open enjoyment of violence or combat. Itachi instead prefers to avoid battle or, if that is not possible, end it as quickly as possible while exerting as little effort as he can. When he does fight Itachi remains stationary, attacking only in defense and to otherwise avoid damage.
Although his awesome use of taijutsu, hand seals, weaponry and ninjutsu, his signature ability is the use of the genjutsu, being able to use it just by seeing the eyes of a person or by pointing with one finger. He can also revert the genjutsu of an opponent just by using his Sharingan. He also posses the Mangekyo Sharingan, a Kekkei Genkai he obtained by killing Shisui Uchiha, that allows him to use Tsukuyomi and Amaterasu, two powerful genjutsu and ninjutsu, respectively. However, after performing a single jutsu of the Mangekyo Sharingan Itachi gets tired and he may not even able to use the normal Sharingan for a seconds as seen when he performed Amaterasu to escape of a trap of Jiraiya. It has also been impplied that his eyesight may be damaged with the use of this doujutsu. Another strange fact of his Sharingan is that he is always using it only disabling it after the use of the Mangekyo Sharingan.