Koreeda said that all the characters in the film, to some degree, are imprisoned by invisible walls. "The mother is restricted by social norms, and the teacher is restricted by his manhood, as well as the school system. And the children are living in this world that the adults have created and they are affected by it, in terms of the violence that is perpetrated upon them. Yet they are able to escape it. It's as if the adults have been left behind, and the children have gone ahead and come to their own self-realization. I wanted it to be a positive realization."