I didn't like Kanae that much either. She felt way too girly and indecisive. Takaki was relaxed and nice, but distant. The only character who seemed to be at ease with herself in the movie was Akari, but that is hard to be sure of. My impression of the movie was that it was about the way lingering emotions affect our maturation. IMO it was kind of apparent that Takaki felt like shit in the last episode because of things he could not let go. He tried to carry all his memories with him all the time when there were things he would be better of forgetting.