Tora (トラ) was a member of the ANBU, working directly under the supervision of the Second Hokage. He was one of the ANBU ordered to watch the Uchiha clan to keep them from rebelling again. Tora is likely not his real name, but a codename. He was said to be very skilled. Endowed with tiger-like strength and walking ability, any target he aimed for had no hopes of escape. (Source: Narutopedia)
Jinin Akebino (通�野餌人, Akebino Jinin) was one of the former members of the Seven Ninja Swordsmen of the Mist. He was evidently very skilled at utilising Kabutowari, a blunt sword that consists of a single sided axe and a hammer joined by a leather strap, which is said to be capable of breaking through any defence. This is achieved by first striking with the axe, before hammering it through the remainder of the obstruction with the hammer, resulting in the axe functioning much like a wedge. The 'swords' construction still allows the weapons to retain their individual capabilities and thanks to Jinin's expertise, both the axe and the hammer can be exploited to their fullest. Manga Debut: Chapter #522 Anime: Naruto Shippūden Episode #265 (Source: Narutopedia)
T�ka Senju (�手桃�, Senju T�ka) was a member of the Senju clan in the time before Konoha was founded. She was a close associate of the leader of the clan, Hashirama Senju. T�ka specialized in genjutsu and was well-known throughout the world for her amazing genjutsu abilities. (Source: Narutopedia)
Ishikawa was the First Tsuchikage who founded Iwagakure in the Land of Earth. In the anime, he was stated to be a member of the Kamizuru clan. (Source: Narutopedia)
Itama Senju (千手板間, Senju Itama) was a young shinobi from the Senju clan. (Source: Narutopedia)
Isaribi was a human test subject under the control of Amachi who in turn used to work for Orochimaru. The test was meant to give shinobi the ability to breathe and operate underwater. Isaribi was one of the first test subjects, and was not the final version. She was sent back to the Land of the Sea to spy on the ships leaving port. Due to her bandages, which were used to cover the permanently scaled parts of her body, the villagers attacked her and vandalized her property. They feared and hated her as she was the only person to return from being "spirited away". Isaribi was promised that she would be returned to human form if she complied with Amachi's orders. To that end she attacked ships and killed a number of sailors under the disguise of the Kaima, a sea monster. Naruto was able to make her come to her senses, causing her to realize that were she to continue killing others to save herself, she would become a true monster. After his defeat, Amachi revealed that he never had a cure for her condition, and that he planned to dissect her once she was no longer useful. She returned with Naruto to Konoha after Amachi's defeat hoping that Tsunade can cure her.