Kyle has no kin that he can recall. Since he was responsible for his own wellfare from a young age, he had work-skills like an adult by the time he was 12 - when he decided to go to Meribia and become a thief. Once there, he met a dirty little urchin who was at least a match for him in rowdiness, and after locking horns for a while they became friends. Kyle eventually told the kid his master plan - to steal Master Mel's fortune from his mansion, even though he wasn't sure how to do it because the guard was too tight.
The kid somehow got a hold of a map that showed how to sneak into the mansion from the sewers below, and give it to Kyle in exchange for a promise to let the kid come along. Kyle, on the other hand, had no intention of keeping that promise, and broke into Mel's mansion that very night. While looking around for a likely treaure vault Kyle came across a particularly ostentatious room. Creeping in, he found it was a bedroom, and his friend the little urchin was sleeping in the bed!
Seeing the kid clean and well-dressed was suprising enough, but Kyle was even more astonished to find the kid was a girl. And not just any girl, but Mel's beloved daughter Jessica! Jessica, for her part, was no less suprised to wake up to an unexpected presence in her bedroom, and screams. In a matter of seconds the guards have caught Kyle.
Mel flew into a mighty rage after learning what happened, and probably would've had Kyle executed over this if not for two things: Jessica's pleas, and Kyle's sheer nerve - he never showed any fear of Mel. So as an alternative punishment, Mel decided to have Kyle dangle from a window of the mansion until he learned his lesson.
But Kyle was determined not to learn his lesson, and hung outside the mansion for 3 days straight. He even went so far as to try to pee on Mel when he passed below. (Yes, this is really in the book!) Kyle's defiant spirit impressed Mel, and Mel offered to make a deal with the boy - he said, "if you root out the bandits lurking in a mountain called Nanza, I will forgive your crime."
And so Kyle set out for Nanza, a lone 12-year-old boy about to battle a band of dangerous theives.
Well, to be honest that's not accurate, since Jessica snuck out and went with him. And those two are a match for just about anything.
