the main issues with yozakura quartet anime adaptions are trying to fit a whole bunch of things in and still leave open endings because the manga isn't over yet
or in the case of the first adaption, doing an original ending because it was made in the early-mid 2000s and original endings were the thing to do
hano no uta was looking solid as forget then it just kinda ended. It was introducing stuff that we'd see later but ended with no mentioning of it because it was following the middle of the manga. Way disappointed in that but I still enjoyed every second even if it is incomplete.