Idk why people thinks it's so hard to believe that anyone with red hair is an Uzumaki? How many people in the manga actually have red hair and how many Uzumaki's do we know of during the manga? The percentages are all about the same. There is definitely a correlation between those percentages. Karui and Gaara are definitely Uzumaki's just for that simple reason alone. Think about how much chakra is requires to control sand. It's not like he's just manipulating chakra from his body, he's controlling the earth. Who knows what Karui's abilities are but a lot of you guys are over thinking and putting too much thought into a simple question with a simple answer.
