Notes as of Chapter Six:
This is interesting and rather melancholy. The English title suggests something much more crude and creepy than the actual contents, though a certain creepiness is definitely present.
The most disturbing element, of course, is that both Riona and her father "use" the robot Forti in the same way (perhaps for similar reasons). While this casts a rather sickly pall over the first chapter, it's hardly mentioned thereafter. In fact, daddy doesn't appear in chapters 2-6, allowing the relationship between Riona's and Forti to develop in comfortable isolation.
The parallel progress of Riona's relationship with Karin is, to me, the most interesting and affecting part of these early chapters. I like the willingness to work in shades of grey, and having been through something similar in my own youth, the characters' feelings and behavior really hit home. I'm curious to see where things go next.
As an aside, Manga about sexy robot girl characters typically grant them more individual personality and emotional depth than they supposedly should possess, often because the robot in question is a prototype model, a one-off variant, or otherwise unique.
Daddy's Dolls seems to be following this pattern, though it's too early to say for certain. While she claims to be incapable of human-like feeling, the depth and complexity Forti's emotional awareness is obvious, as is her compassion. And it has already been suggested several times in various ways that she's not like others of her kind.
Giving Forti human qualities diminishes the sad creepiness of the soulless woman-object used by wounded people for sexual gratification and as an emotional crutch, but it amplifies the ick creepiness of the docile female slave who provides these services on demand. That tension is pretty much the robo-gal trope in a nutshell. It's always kind of gross, though it can be handled well.