Well my initial concept was of a girl that isn't directly related to any of the more well known clans or characters or any of that stuff. She's an outcast in her family not because she's brooding or mean or edgy but because of her low chakra and difficulty in using ninjutsu. It's seen as an insult by her grandparents and siblings that she has to use Kote to compete with others who have a more natural affinity and ability. She's come to dislike using it as well but realizes that it's integral to her position. With her resentment comes more focus on taijutsu (or bukijutsu, undecided) using the Kote to enhance it. She's taken what she and her family sees as a handicap and attempted to turn it into a strength. Her resentment/rivalry of the hero or whomever stems from a predisposition to disliking people who flaunt their ability - assuming of course the rival is someone that DOES that. 

That's sort of a rough initial concept but I can sleep on it and maybe drum up others.