kokoro wo hitotsu ni / 心を一つに
This phrase, the subtitle of the film, can be seen in a single scene. It translates to something like “our hearts as one,” but it means much more.
The word “kokoro” is generally translated as “heart,” but that isn’t quite an accurate translation. In addition to implying the center of feeling, the place where love and hate and sadness come from, it also implies the spirit of a person, the mind and soul (although, the Japanese idea of a soul is completely different than the Christian-European one in that it is not unchanging and it is possible to possess more than one). So, the phrase “kokoro wo hitotsu ni” speaks of hearts and minds acting together with a single purpose.