I'm trying to piece together what happened here, but I'm pretty sure the answer is we just don't know yet. Here's what we do know now:
* Shigisawa Taikan (her grandfather, also called Adolf?) performed several strenuous tests just to see if she was ready for the world and had reached the level of a college student...
* Her grandfather revealed something about her parents, presumably, but it must have come with some sort of heavy price or reveal of what would happen to her if she kept on this path. Very curious why it would be something Mozuya would be very happy about, but then suddenly crushed by.
* Clearly something is wrong with her adopted mother and it's something serious. They've been hinting at that for a while now (trips to the hospital all the time?).