That sounds good to me. Though the master won't be entering the tournament (probably finds it beneath him?) should we have his son be sort of the top contender, even among the other instructors who enter? I figure we'll need to focus on developing the main adversary and not worry too much about the others competing. So Ryuuto Tajima is the son. I do like the idea of the daughter (maybe they're both twins, around 16 or 17? Or are you thinking older?) reforming and seeing that her family's way of life isn't so great, possibly finding a friend in Yahilo and Kaoru.