To be doubly fair, it is actually fine to give an author the benefit of the doubt even if one does see the tags,
and still complain afterwards. This manga's depiction of rape is pretty disturbing compared to a great deal of other content here with the same tag(s).
i mean yeah everyone is allowed to express their opinion of something, negative or positive if someone has a problem with the writting, characters or any other aspec of the story that´s prefectly fine. But if you´re main complain is "there´s rape i hate it" the answer is as simple as don´t read it, if the mere tought of that action being performed even in a fictional setting sickens you, just don´t read it. Why would you subject yourself to something you know you´re gonna hate?