Banjo was not always partners with Kazooie, this is both of thier stories. Bango was just a kid with his baby sister,Tooitie, and he had no parents, so Banjo was on his own. Bango never had a friend to be with when Bottles took care of Tootie, so he walked around spiral mountain. All he could think about is having a friend.
Kazooie had a terrible childhood. Her parents died when her house burned down when she was a baby, and a priest took her in. Years later she had to be shipped of to a home-school, where the main part of the terror began.
Kazooie started out by being a good student. Then while she was eating lunch, a bully came up and was digging through her bag. He found Kazooie's Kazzo that she found whild digging through the ground for treasure. So they got into a big fight! Then, someone grabbed Kazzoie.