It's really fantastic piece of work ... but it's funny (and it is laughter through tears), that the ending of "Good Ending" is really bad. Last +-20 chapters (exclude very last chapter) are totally unmanaged, and author is dropping to total mad story spins.
And Touru was totally unmanaged from time when he comes to real life contact with Yuki ... I think he ruins the story a lot.
Author just forget about how Yuki overcame her trauma ...
As some people below mentioned, it would have been better, if it was shorter.
But lets look on its brighter parts.
It is the first manga that I read, where characters are not acting like they are totally insane. Where, if one character is in love, and is asked to help another person to get the person she loves, she refuses (character 1 - in love with char. 3 - is asked by char. 2 to help get the char. 3, and char. 1 refuses). There are so many situations, where "real life logic" wins over a "manga logic", and thats really enjoyable. Story spins and feeling changes are quite believable, all characters are very well managed, have good character builds and are acting just like they should - according to personality.
Lead male character for me is one of best so far, because he acts just as I would be acting (most time of first half) 😀
Final: Really enjoyable manga, even if its bit confusing sometimes. Author is playing really well with feelings of reader and keeps shortening and stretching out the distance between main chars, what creates really good tension. Even if last chapters are really badly managed, other parts are incredibly good, and that makes it a really worth-reading manga with heart-grabbing story.