If anyone would like to use any of these characters in one of their fanfictions, say so first. And some of them really go a lot better together than alone.

Niroshi Haruka
Age: About Naruto's age
Basics:
She has a bloodline trait that allows her to completely control her body, to the last cell. She never knew her father, until later in the story. Born in Sand Village, her mother died of illness because she wasn't very skilled in using the trait, when Haruka was pretty young, about four or five. She lived with her best friend at the time, Kazuki, and his father, Arata. However, two years before she graduated from the academy, Arata died on a mission. Kazuki managed to graduate before the money Arata left ran out, but as a Gennin, he didn't make enough money to take care of both of them. So he ran away, leaving Haruka to her relatives in Leaf Village.
Her friends (a bit of a makeshift family) are as follows:
Kazuki, Arata, her mother, Gaara, and Naruto, as of yet.

Kazuki
Age: About a year older than Haruka
Basics:
Never knew his mother. Grew up in Sand Village. Left Haruka when financing became too much of an issue. Read and figure out where he went.

Airi, Kazuki's teammate...
Will add more later. Admittedly, not all of it is entirely complete, but...live with what's here for now.