I'm currently working on a fantasy story, and I'm having trouble getting ideas for a main plot. I already have a subplot: One of the main characters, Kime (a fox/human), wants to find out why her supposed father sold her into slavery when she was a little girl. Ryuka, a fellow slave and also a foxkin, promises he'll find a way for her to see him. Only thing is, Kime's father is the king. The other two main characters are Leona (a cat/human who runs a martial arts school while trying to stay hidden from her family), and Greg (a wolf/human who gets himself into trouble constantly and is a thief). Yeah, I know it sounds cliche. I'm just wondering if I would able to take the sub-plot and add to it so that a main plot might develop from it.