Gaara is the third and youngest child of the Fourth Kazekage and Karura, and the younger brother of Temari and Kankurō. Before Gaara's birth, his father ordered Chiyo to seal the One-Tailed Shukaku within him, in hopes that Gaara would become the ultimate weapon for Sunagakure as he was the only one of the Kazekage's three children to be compatible with the beast. He was born premature and therefore, was an unusually small and frail infant. Before she died, Karura passionately held her son, vowing to always protect him. Gaara was trained ninjutsu by his father, but raised mainly by his maternal uncle, Yashamaru.
Because of the power of Shukaku, the villagers of Suna hated and feared Gaara. Seeing him only for the monster sealed within him, for a time, Yashamaru seemed to be the only person who cared about Gaara. When Gaara would unintentionally harm others due to the subconscious abilities granted to him by Shukaku, Yashamaru was the only one who understood that Gaara hadn't intended to harm anyone. The village's council, however, did not see Gaara in the same light, and viewed Gaara's frequent attacks upon villagers as a result of a failed experiment that was a threat to the village, and Gaara's father did express disappointment at this lack of control.
Because of the danger Gaara imposed, his father decided to test him and told Yashamaru to corner Gaara psychologically, and lie to him about his mother to see if Gaara could retain control of Shukaku. As a result, Yashamaru told Gaara that his mother never loved him. He also tried to assassinate him, however he failed as Gaara dealt a lethal blow to him. But when Gaara realised who it was, he was horrified and screamed before bursting into tears.
Gaara loses control and allows Shukaku to go wild.
Added by Blackstar1
Although Gaara tried to consider Yashamaru's attack as an order of the Kazekage, Yashamaru lied to him, by saying that he had willingly accepted the mission to kill Gaara. He also lied that he never truly loved Gaara, and told him that killing him would avenge the death of his sister, who had named him Gaara after the phrase "a self-loving carnage" (我を愛する修羅, Ware wo ai suru shura), a sign of her intense hatred for Suna, not as love for her son. In the last ditch effort to kill Gaara, Yashamaru detonated a number of explosive tags covering his body, asking Gaara to "please die". Using his sand, Gaara survived the blast, and lost the only person he thought had cared for him, while not knowing the true reason. Gaara then used his sand to etch the kanji for love (愛, ai) onto his forehead, indicating his first actual injury. Right after this, he lost control and transformed into the Shukaku, rampaging around the village before his father stopped him with Gold Dust. Since this incident, Gaara became an aloof and cruel person who would kill anyone to prove his existence and to obtain recognition from the village, all the while giving up his desire for friendship.
