Kinda what you’re looking for: a toy with sadness
http://www.mangago.zone/read-manga/theo/ not exactly slave but it's cute
http://www.mangago.zone/read-manga/goshujinsama_to_wa_iwasemasen/
actually I would really like to find some more too, cause I don't think I've ever read something exactly like that
Royal servant was really good
Blood Bank?
Yea that one is good I wish they had a lot more like those whoever did those like royal servant and blood link are talented
Blood bank not blood link, although blood link is good too
Can anyone recommend some slave like manga, both yaoi or regular is fine, i like them to have some sexual scenes or at least romance, i can handle if there’s is a lot of sexual scenes but only if it has a good story line, like royal servant or something, I usually like the master to be sweet to the slave or servant, or be mean at first but become sweet over time, i don’t want some long drawn out stuff either I want something where it doesn’t take 20-30 chapters just to see them kiss, I want an actually good story line.