Hello!
yes, with Azula I was thinking that a member of the fire nation aristocracy purchased her sentence so that she serves it out in house arrest at his estate.
we can remove the non con and it be she has to abide by his rules in order to maintain some semblance of freedom on his property. She wears what he tells her to wear, earns privileges following guidelines he sets for her. From rules such as her clothes need to expose her breasts or ass on certain days, or she is give him a blow job at breakfast, to public sex or blowbangs, other sexual acts we can discuss further on.
It can progress to a point where she’s earned her right to be set free, but chooses to remain as a bimbo or freeuse slut.
for piper, it’s less of a planned idea and more curiosity of the character. It could be she’s thrown out because of her newspaper and takes residence at another community but has to resort to prostitution or the like to get by.