Many Japanese would say that this is the best song of the last century. It is not exactly certain whether she is leaving on the train to Tokyo or he is, but certainly they were lovers or very close friends. It is either a weakness or strength of Japanese that we do not always know who is being referred to. She is now in her forties [edit: more like sixties—my how time flies] or so and her generation produced some of the best music ever in the language. imo oc. I cannot get beyond two bars of this song without blubbering. Thanks Iruka-chan.