Hmmmmm
I feel terrible reviewing this film, because Koreeda is my favourite contemporary Japanese director, but this was definitely the worst film I've seen by him.
I think I know what it lacked: conflict.
Everyone was too nice, and there was just nothing threatening the little utopia the four sisters lived in. It just lacked that threat of violence or danger that his other films have. I also found the musical score a bit dull.
But it was beautiful, like all of his films.
Just not one I can score highly. 6/10