So he's never actually met her, and is just obsessed with her for no particular reason? Why would he even be adopted if she had died? And why would the family search for her if she was supposedly found dead? Also, the family KNEW that she was locked up in that room and isolated? Why were they okay with that? Also the older brother seems to already know the fake is a fake, so why does confirmation seemingly break him (ch.1)? This story isn't making much sense to me right now.