Backstory: Callum joined the core IMC military when he was seventeen, doctoring his papers to properly lie about his age. After two years, he deserted. The routine, the orders had become stifling. He thought about becoming a mercenary and working with the IMC, but soon headed for the frontier. Once there, he joined up with the Militia, and received Pilot training. However, the militia, he decided, wasn’t for him. He bounced around for a while, before finally finding a home among Gates’ 6-4. The ability to decide who he fights for, coupled with the tight-knit nature of the group sold it for him. Callum has spent close to half his life as a warrior, and The 6-4 is the frist group he’s fought for because he wanted to. He’s been with the 6-4 for two years now, and he has no plans of leaving.
@Buddha Right? That would only make sense. A little research gives me people saying they've heard that, and there's a bit about it on the Wikipedia page. Can't find any real sources. One those things that everyone has heard, but no one remembers where they heard it.