To be honest, Tomoe makes no sense, character wise, but I like the overall plot of the story as well as Zen's character and backstory. That make sense. I am not going to talk about the rape stereo typing in this. Japan looks at rape and rape victims differently, compared to us in the Western world. I know it sounds weird, but the views are just different. You should google information about it, if you want to know why rape is sexualized (or romanticised) in a lot of mangas.
Hard X Heat X Heart