they both have demons inside them called demon foxes gaara is i think the 3 tails and nartos the kyuubi (9 tails)
<edit> actually gaara had the ichibi (one tail)
- i don't think its a fox... it doesnt even really look like a fox. gaara has the shukaku. a one tailed thing. it doesnt really look like an animal. and naruto have the 9 tailed fox in him. their opposite jinchurikis. the shukaku is the weakest of the tailed beasts and the kyuubi is the strongest of the tailed beasts.
naruto and gaara were both hated when they were kids. but naruto made friends eventually. and gaara didnt have any friends. gaara trusted only his uncle. but his uncle tries to kill him and the shukaku or gaara kills him. many people tried to kill gaara. nobody tried to kill naruto (when he was little i mean). gaara never made friends. naruto did. even though naruto was the strongest jinchuriki and gaara was the weakest jinchuriki, gaara was hated way more than naruto. (guess because it was more obvious espacially from his insomnia and he started killing people). even when gaara apologized to a kid that the shukaku hurt, the kid still hated him. even tamari and konkuro didnt like him until they become a team i guess