I think you have a good point. In the manga, the Minagawa family intrigues drag on too long, and there is only one excerpt that explains the mother's problem, which will allow us to understand Yoichi's family dynamics better. So I feel you, that side was disappointing.
As a teenager, Youichi is forming his identity, and part of that comes from understanding where we come from and how we relate to our parental figures, but somehow this was presented in such a sloppy manner. So I agree, they drag the story out unnecessarily, but it's still one of my favorite mangas. Despite all of this, the story between Sakurai and Youichi is lovely. Hidaka Shoko is simply sensational. I love her.
I'm trying to like this as what the comments are saying but it doesn't click to me. Why they are so invested in their parents' issues that it affects their life as a whole? I don't know how to put my finger into it but it's just all over the place for me. I'm contemplating whether this story just have a deep meaning or this plot is really complicated for me to understand. This story basically revolves in drama and the romance is just like 20%. Lolol somehow I believe that the uke is pinning the father image to the seme. The age gap is....ridiculous. I never hated that kind of trope but arghH this is driving me crazy. I spent my whole day-off just for this manga.