Response to PBR:
I think what makes it so wrenchingly sad is precisely the lack of sorrow and regret of everyone except Noriko (hope I remembered her name—the one who married in) and the father (who also married in)—oh, and the younger daughter, I suppose, but the film undercuts that somewhat, I think. I find it tremendously powerful that the only two people who grieve substantially out of anything more than cultural expectation are the two people who chose to be a part of the family. If what the film did were simply portray the death and grief (even if in a brilliant way), I would accept your point. But the way that it portrays the lack of grief every bit as much, and does so in a sympathetic way, so that the other family members aren't just totally unlikeable, is what makes the film so moving. For instance, the youngest brother—he clearly begins pathetic, and then he has that one scene where he thinks to himself how he will improve. As the viewer, you (rationally) have to treat that with distrust—why should mere grief be a motivator like that? he has to convince me that it really means that much to him. etc.—and that distrust is later proven right. But it's not just distrust, it's distrust and hope, and in exploiting that, Ozu creates a moment that captures that profound disappointment when someone squanders a crucial opportunity to improve himself.
Sure, there is a remarkable lack of regret among the direct family members. But that seemed so logical to me. And this is exactly why the first hour and a half of the film felt much more sad than the ending. Because those are the moments when the children's lack of interest in their parents' lives had actual weight. Their behaviour after the death of the mother seemed natural, as opposed to their behaviour before their parents' departure from Tokyo. I'm not sure what to make of that younger brother's story. I will have to re-watch the film to get to the bottom of that. I see now that I have definitely not gotten everything out of this movie that there is to find. To make matters worse, I suffer greatly from the "all look alike" syndrome when it womes to black-and-white Ozu movies so I might have confused some of the characters at times. I'm getting better at this though, now that I'm watching more of his stuff.