Hey great story! But I would like to point out that you might want to change your mind about Hermione and here's why:
I know this woman, been friends with her for about 10 yrs she is drop dead gorgeous, worksout and keeps her body in outstanding shape she is also the exact same character as Hermione in fact I would have to say that rowling woman copy her hermione character from my friend: No-it-all bookworm. according to her she is always right and I and of course mostly guys are always wrong! Very bossy nature, dominate right! Wrong, I found out one night were sitting around drinking wine on a weekend night, after first bottle (weve always been able to talk about anything and everything including sex, were friends only, never been intimate with her but have seen her naked alot, loves to walk around naked in front of me)she dropped a bomb on me, she admitted after awhile that she has always had this fantasy of being tied up and dominated, after much more coaxing I found out she was very subservant, in the bedroom dept but had never gone thur with it, not being able to trust a guy enough. I guess I should of seen it earlier cause she will do alot of things to please me, like walk around naked, but since she's more like a sister and even though I find her very attractive I dont get turned on by her, but she wanted me to tie her to a bed once while she was naked, she just wanted to know what it felt like, hell she even told me if I was horny and needed to get off then go ahead and do it, in fact at that time she told me if I ever needed sex or to get off she was available, in fact she told me she would pull her pants down and bend over a desk or chair anytime I wanted, really submissive, but again you wouldnt see it unless you were looking for it.
So again you might want to change your mind about making Hermione one of his slaves.