@Scynix you are probably right in your thought, but right to the chapter 4 its said that she become sex slave so it was to be expected
My thought is, it wont change who (male) did buy her, she most likely have the same end, its better be with Michio than you know who right? about the other slaves, it might be that they ride on the flow, seeing how Roxxane was cherished
Tell the true, I did feel that the MC was forceful with his slaves but only the latest did give me the feeling of rape (no more comment to not spoil)
About if have difference of LN and manga I can't say anything since didn't have read it, only WN, but I think
they have made it lighter on manga thinking of the range (age) of the public that will access their material, still weird with all that boobs show, but hey it will be really boring if you take every thing from it
Even Japan have a little of restrain on few topics, the most clear proof of this is the Ryuga Seal 卍 (Manji "swastika") from Naruto, its an ancient symbol but sadly most people associate with nazis, well this comment was a bit of topic, but you can get the overall idea with this