I first reading Bitou Lollipop and come to this with full excitement. Iketani-sensei gives us many very interesting plot. It's natural to be pissed off with the development but her stories are well-build. The characters don't have to perfect, you should do this and that and blah blah blah. I simply love how things going and ended. She is one of best mature shoujo author we can get.
I clicked the spoiler tag now but I can't wait for the next chapters!
UPDATE :
I have read the last 44 and its epilogue. I can say with confidence I love the ending. It's sad and I got to see
A-chan's feelings more clearly. Everything go back to them in the end. It's not something acceptable (I myself won't forced you to) but their happiness matters.
basically after the entire manga is being spent on her development and remembering stuff on her boyfriend, at the very end she gets together with her step brother...