He was a monster, that's what they said. As a child you befriended this monster.

When you were ambushed out of the village, he thought that he had lost you, soon enough he thought that you had abandoned him for what he was. The rage boiled up inside of him, he became the monster everyone thought he was.

Now you come back to the village, you meet Gaara again. He isn't that monster anymore, he's the Kazekage.

He won't let you leave him again.