At first glance the story looks very dramatic - a girl with a traumatic past, a boy who feels guilty for all that happened to her, a blackmailing punk... Everything seems ok except that the author has no idea how people deal with such problems in reality O.o.
I've got an impression that everything (despite the horrible story in the bg) is extremely idealised and infantile - the heroine is utterly naive (not to say stupid) and easily manipulated like no one else (maybe except her even dumbier brother); the villain (who's as evil as a squirrel) plots against the main characters and backs off as soon as hardly anything goes as he planned.
That manga just tired me as hell. Thought that I would read something deep and dramatic, yet I got a boring and naive story that would never turn out this way in real life.