this chinese structure where the girl who's supposed to be the protagonist is actually just a plot device to make things happen most of the time is really common...really not to my taste. I was a fan of the arc where she was at the basketball court, but other than that, up to chapter 49 she hasn't done a single thing. instead, things just kind of happen around her because that's how the author wants the story to go. there isn't a strong sense of grace/hans' actual character as an individual at all.
that, plus the thread of hans' past life is still just hanging. it's been set up too early and now it seems like a mistake. other than the spooooooky gov. project there's no real reason for the gender bender part either.