@HoneyPopper The thing about it is we never really got a good idea of how Hayase's clan really was other than her fabricating history to try and achieve power through Fushi and her indoctrinating her children and the ones who came after. So Mizuha's mother being obsessed with making her daughter do all sorts of things doesn't translate into a family trait and only seems like an isolated case. It could be, is just that the author never bothered showing any of that in depth
much like with the world building tbh
Mizuha's random fixation with Fushi is completely by chance. If her mother didn't give her reasons to want to run away, if she wasn't so isolated from her peers due to being "perfect", if her grandfather wasnt stranged from her mother, then Mizuha wouldnt have gone there to seek shelter and finding out about Fushi.
In the end, she fixates not so much with Fushi, whom she barely knows, but much like her ancestor, she fixates with the
idea Fushi represents to her. She says it herself, she had a void in her life and thinks "aquiring" Fushi will fullfil her existence because lo and behold, that was her "destiny" all along.
Personally I think is kinda lazy, writting wise. And made worse by the seemly queer baiting between Mizuha and Hanna. But yeah I do also think the story doesn't have any real direction, which creates more problems/makes the series stale.
The author's strongest point is characters and their interactions, but in a fantasy setting like this, this kind of makes the story bland.