It's garbage. It would be one thing if it was a massive satirical work on the tropes and misogynistic characters of other manga ala Voltaire, except it's NOT. It's like example number one of those things. Anyone who read this and thought there might have been redeeming parts needs to step back and look at the whole work's message as a whole and critically think about it.
Well, as a quality story about good and evil and the perception of both, it does suck. Badly. The message itself is misogynistic and unacceptable, and in the end everyone is forgiven-- all the boys and Tsuki, which essentially negates everything they did wrong and says that it's forgivable to do terrible things if you were just doing them because your boss told you to, or that everyone else was doing it.
But I don't look at it as something actually applicable to society. I think it's fucking ridiculous. I think it takes an overly optimistic view of abusers and victims, and the reason it happens in the first place. Morals are completely absent in this work, which is why I can't take it seriously on any level.
But at the same time I kind of like how it was told. I am able to detach the meaning from the story and look at the one part I liked, how it was told, and I am able to say I liked it. Maybe I'm completely wrong this story doesn't deserve to be liked in any shape or form, but I find myself enjoying it a little.