She spent her childhood as a nerdy shut-in and got bullied a lot, one bullying session however, cost her a good chunk of her tail. The bully was punished for what they did and was severely sorry, but the event still marked a turning point for Runa, from then on she began to train herself seriously to try and become stronger, more cunning-and of course faster. All the training paid off in the end and she soon evolved, of course her tail never grew back, but her self-confidence has more than doubled, and now it nearly borders on arrogance.