Unlike a lot of people here, I actually thought the ending was really strong and mostly fitting for the manga as a whole and the characters, especially Ryo. Part of me certainly hoped for happiness for him, but at the same time I knew it almost certainly could not end that way and would not feel right had it.
The only thing I did dislike about the ending arc was the use of the story being read by the sister. It is kind of an overused plot device and felt out of place in this manga, especially injected at the very end as it was.
I agree, however, that the manga overall was really inconsistent and somewhat repetitive. It did not seem like the creators knew what story they were exactly trying to tell, on the whole, and that is not surprising considering that there were apparently creative differences that led to one of the creators exiting the project halfway.
Still, I do not think it is shit as some people suggest. There is a lot of shit out there were stuff just happens for no reason, with no real emotion (or the emotion feels really forced). Not the case here. Despite all its flaws, there was real spirit in this manga, and it evoked real emotions in me. And, although the thread holding it together was a bit tenuous at times, it was there. And, as I implied above, I do believe the beginning and end do suit each other.
You have to be paying attention and think though. This manga does not spoon feed you.
Objectively, I probably should have given this an 8/10, but something about how it touched me made me give it a 9, at least for now.