the ongoing joke can be whatever vash wants me to do, i'm gonna double the price because it's always a near death experience. also it's completely not known! koz's ma stole a bunch of money and ran away from korso while she was pregnant and korso's cronies ganked her eventually but never found or cared about koz. he was orphaned pretty young and has been hopping from terminal to terminal and world to world since he was like 13. i'd love to say vash saved his skin like years and years ago when he was collared for stealing and that's how they started working together if it jives!