If you read some dialogues there were some scenes were you could see some genuine feelings that were more than lust ^^
Not that it's a bad thing either way but at the end of the day neither you or i can say if something has to be this or that to be considered romance. Since people are different and what for some is platonic can be for the other romantic ^^
Also prostitution is "The practice of engaging in sex acts in exchange for money". So when they do it for free then they aren't prostitute. Either way nothing bad but just so you know.