Gamahiro is a giant toad that resides on Mount Myoboku. He sometimes called: "Hiro". When Gamahiro first appears in the anime, his skin is colored green and brown. This is updated to a light-blue-greenish color for the Invasion of Pain Arc, keeping up with the manga's coloration. Though he was first summoned in part I, he was not named until he was summoned again in part II. Though Gamahiro has spoken in the anime, he has yet to do so in the manga.
Karura was the wife of the Fourth Kazekage, and the mother of Gaara, Kankur�, and Temari. Against her wishes, her husband had the spirit of Shukaku sealed within Gaara before he was born. During his birth, her life was used to power the sealing process. Before she died, she cursed Sunagakure, hoping her son would avenge her death and the horror she had been put through.
Nawaki (縄樹) was the younger brother of Tsunade and the grandson of the First Hokage. He was very much like Naruto Uzumaki in both appearance and personality and like Naruto, Nawaki also had the dream of becoming Hokage one day. He shared this dream with his sister on his twelfth birthday, who gave him their grandfather's necklace in the hopes that it would help him achieve is dream. The day after his birthday, Nawaki died in battle. His body was so heavily mutilated that it was beyond recognition. Orochimaru would later offer Tsunade to bring Nawaki back to life, together with Tsunade's lover Dan, in exchange for healing his arms. The resurrection would require a human sacrifice, though. She ultimately refuses, realizing that Nawaki and Dan would not want her to sacrifice the lives of others in exchange for theirs. (Source: Narutopedia)
Kaiza (カイザ) was a traveling fisherman, who came to the Land of Waves to seek opportunities. When he saved Inari from drowning, he took up the young boy to teach him about life and protect the things that were precious to him. He married Tsunami (Inari's mother) and acted as the role model for Inari. When Gat� tried to take over the Land of Waves, Kaiza tried to stop his business. Gat� used him as an example to people who had hoped to stand against him, by having his goons cut off his arms and killing him. (Source: Narutopedia)
The Second Hokage is the younger brother to the First Hokage and Tsunade's great-uncle. As the brother of the First, the Second Hokage was a member of the Senju Clan of the forest. The First and Second together fostered Konohagakure into a growing village. He was once the teacher of the Third Hokage. He was hailed for being the greatest master of water jutsu, being able to create water from nothing, allowing him to use any Suiton jutsu without requiring a source. He is later revived from the dead by Orochimaru using Impure World Resurrection to fight the Third Hokage during the Destruction of Konoha arc. His soul is eventually sealed into the stomach of the Death God, along with his brother and Orochimaru's arms. Along with his brother and Madara Uchiha, he was also one of the founders of the Hidden Leaf.
Mikoto Uchiha was the mother of Sasuke and Itachi. She was also Fugaku's wife. While she was alive, she seemed to like Sasuke better where her husband seemed to prefer Itachi. She was a very good mother, seeing as how Sasuke was able to talk to her better than his father. At one point, in order to cheer Sasuke up, she says that when she and Fugaku are alone Sasuke is all he talks about. Although she was Itachi's mother, she did have some suspicion about Itachi and knew that something was up. She was found dead with her husband during the Uchiha Clan Massacre, killed by Itachi.