Rape/abuse is not my usual camp but this has an interesting psychological plot in it.
However, I am amused that it takes a story to be this realistic to grant the warnings about rape and abuse in here. This is the correct way to present a manga. It has clear warnings of what you are expected to read ( so I don't really get the people who read it and are complaining about the hardcore stuff). Compare that to the tons of yaoi stories that has the 'rape as love' trope but all you get is a 'cute' summary in the page and in the comments - hardly no one calls it rape and warn other readers about it.
All stories that have rape/abuse/sadism/non normative sex should come with the warning -- like this one is correctly doing it -- no matter if it's realistic like this one or the ridiculous 'rape me and I'll fall in love with you' twilight zone yaoi rape.
Feeding lamb