Damn no Diabolus Ex Machina, though I would say there was no 'proper' foreshadowing (I don't thing foreshadowing is necessary though, as... this is what real life relationships should look like, not beating around the bush (The mc though took 10 years...) I suppose I got customed to all millions...
Zetsubou sensei anime explained it pretty good actually
How people with scary appearance, appear scary, so people take them for kind, as otherwise it will be stereotype, which lead their bad deeds be turned to blind eyes.
Cause it isn't
No humans can swing their personality so easily. Even if they can, scars will remain. I can see how Sumi isn't like in a better position then the beginning of the story itself.
Heck it doesn't even talk about 'Hope' or anything, it's simply that 'something happened' and she is...