This is not my story idea, another person had posted it somewhere else and didn't get any responses. so I thought i would post it here in case anyone would be interested in writing it.
two ideas that one other person came up with are;
The concept is, an AU fanfiction where for some reason Hermione is cursed to act like the Malfoys house-elf. Meaning she must obey any order given and must be naked.
this can be around her friends or she can have been taken to someone else's estate with out her friends knowledge.
The rest is pretty much up to you, you could use traditional punishment or make stuff up with magic.
two ideas that one other person came up with are;
all of her pubic hairs magically plucked out until she is permanently baby-smooth.
And to have her own wand transformed into a dildo of various sizes that drives to almost to orgasm regularly