For the first fifteen years of his life, Gaara had two guardians. They tried their best to protect him every single day. They were not always successful, but they were always there for Gaara. His two guardians were probably the most unlikely duo anyone could imagine. The more obvious of the pair was Gaara's mother, Karura. The second guardian was none other than the demon who was often cited as the single being responsible for ruining much of Gaara's life, Shukaku.
Though many of the villagers were completely oblivious as to the true source of Gaara's absolute defense, the fourth kazekage and Yashamaru knew the truth. Though she died shortly after giving birth to Gaara, Karura still managed to protect her youngest child. Her love for him was so great that it powered one of the most thorough defenses known to the shinobi would. Karura never got the chance to watch her son grow up into the noble ninja he is today or to tell her son how much she loved for him during a time when Gaara could remember her, but her undying love lingered to protect Gaara in any way possible.
That love infused sand protected Gaara from most physical wounds anyone tried to inflict on him. Even Gaara himself could not penetrate his sandy shield. The sand would leap forth in times of need without Gaara having to call upon it. When Gaara tried to cut himself with a knife, his mother's love kept him from hurting himself. When Yashamaru blew himself up within a few feet of Gaara, the sand sheltered him from the explosion. Unfortunately, the shield could be penetrated through the use of brute force or it could be bypassed by extremely quick or crafty techniques. Even if the primary shield failed, a layer of sand covered Gaara's skin to soften any blows that managed to land. This secondary defense was too thin to completely prevent harm, but it lessened it much as a mother's kisses could almost magically decrease the pain her children experienced through bruises or cuts. That being said, Karura could not shield her son some physical harm completely nor could she protect him from emotional harm even if she desperately wanted too.
Though few realized what Karura did for her son, nobody ever understood how Shukaku tried to protect Gaara. Many shinobi erroneously claimed that Shukaku was the source of Gaara's sand shield. Though his sand was indeed the medium for that defense, Karura's love drove it rather than Shukaku's desire to survive. However, that does not mean he did not help his host in other ways. Being a demon who had rarely ever been the recipient of compassion, Shukaku could never hope to relate to anyone else in a normal manner. He did take pity on Gaara though. An outcast among the tailed beasts, Shukaku knew how it felt to be alone with almost nobody to care for him. In his own twisted way, he tried to help his host and was the closest thing to a friend Gaara had from the day Yashamaru died to the day Naruto knocked some sense into Gaara.
In many ways Shukaku's attempts to help his young host could be perceived as harmful. His actions did indeed have many negative consequences, but his intentions were good. Shukaku never let Gaara sleep except to allow the beast to use his body in dire circumstances. Permanent insomnia made Gaara emotionally unstable as well as mentally unstable for a time. He could barely control his often violent emotions and for many years his weakened psyche failed to recognize the attempts at friendship made by his siblings. But sometimes it pays not to require sleep. Without a constant awareness of his surroundings, Gaara could have been killed quite easily by ANBU members or other highly skilled assassins from his home village or elsewhere. But he was always awake. On the rare occasions when Gaara failed to notice attacks or could not naturally react quickly enough; the eternal protection provided by his mother could almost always do the trick.
Shukaku's more subtle tactics proved to be even less likely to be seen as helpful. Though Karura almost completely controlled Gaara's defenses, Shukaku affected any other movements Gaara's sand made. He could whip it around in an attempt to scare off potential attackers or send it crashing into victims as he pleased. In Gaara's younger years, Shukaku's control of the sand was nearly absolute. His influence waned over time as Gaara began to master his powers on his own, but Shukaku's control of the sand was mimicked by Gaara's to such an extent that even the fourth kazekage couldn't tell whether Gaara or Shukaku was attacking him at first. Humans could never quick grasp the logic in Shukaku's methods of using Gaara's sand. They believed scaring off both potential friends and enemies could only cause harm. Shukaku's own experiences forced him to believe differently. During the brief period he spent in a human form without a host to bind and control him, Shukaku had witnessed the cruelty of mankind first hand. Humans had screamed at him, cursed him, and tried to kill him even when he had made feeble attempts to adapt to their society.
The tailed beasts are thought by most shinobi to be hate filled monsters with no positive emotions. Though he was never truly human, Shukaku had the potential to feel any human emotion from anger to love. His lack of direct positive experiences with any living creatures prevented him from experiencing many positive emotions, but there was one human so filled with love that she managed to make Shukaku experience both pity and complete and utter devotion for the first time in his long life. Before Gaara was born, Shukaku spent months inside Karura's body waiting for his newest host to be born. He saw and heard everything Karura did from the outside world to the deepest recesses of her mind which remained unseen by anyone save Karura and himself. Peering deep into Karura's soul, Shukaku did see her fear of him and what he would do to her. But he also found things that he didn't expect- love for Karura's unborn child and acceptance of her inevitable death. Shukaku had fully believed that Karura would express nothing but hatred towards her last child but instead she wanted him to be born, to meet his siblings, and to live a long, happy life despite having Shukaku sealed into him. Shocked by Karura's love for her entire family, including her son whose birth would undoubtedly kill her no matter what Shukaku did and her husband who had chosen to sacrifice her, Shukaku couldn't help himself from feeling moved. As Karura vowed to protect her son forever, Shukaku promised to prevent Gaara from suffering as he had suffered for hundreds of years.
By lashing out at almost anyone who approached Gaara, Shukaku tried to prevent Gaara from forming bonds which could hurt him later on. This strategy still failed thanks to Yashamaru. A single explosion turned Gaara's world upside down and shattered any hope he had possessed for a brighter future. Shukaku nearly broke down in tears when he saw his host's spirit snap in two much as his own had done. Picking up the pieces of Gaara's shattered mind, Shukaku pieced it together himself. He tried to create a human with no remaining ties to humanity who could never be harmed by another human again. What he created instead was the shell of a once cheerful child. Filling Gaara's hollow heart with as much hatred as he could, Shukaku still failed to fill all of the cracks in Gaara's soul. Deep down, the boy still craved human friendship and love. He was torn between shutting himself off from the world completely and running to it with open arms. Only when Naruto made Gaara see the error of his ways did Shukaku realize his mistakes as well. Slowly shutting himself off from the boy he had grown to treat as his own child, Shukaku allowed Gaara to become independent and show the world what had remained hidden for so long. Sure Shukaku tried to keep the boy on his toes by giving him a bit of trouble now and again, but overall he allowed his host to blossom into his own person. By the time Shukaku was torn from Gaara's body, he was proud of Gaara and had nothing but respect for the child he had tried to shelter for so long.