Akira Kurosawa knew how to get in touch with human nature through his art. With his visual expressiveness and storytelling, he could pierce through his subjects, even in his big and occasionally comical samurai films, and find the elemental things do work. What he probably learned off of Rashomon probably helped out with Ikiru (To Live), a story of an old man who finds out he will die within a year, as both stories deal with perceptions of the significance of a life spent and a life wasted. Though that was to a different degree in Rashomon, with Ikiru Kurosawa expands into full-on existentialism.
The old man Kanji Watanabe (in a wholly believable and often heart-breaking performance by Takashi Shimura) knows his life hasn't amounted to much as a (chief) clerk for the city. He knows he hasn't had a great kinship with his son. He's accepting his fate with a heavy soul. One of the tenets of existentialism is that there's free-will, and the responsibility to accept what is done with one's life. Kurosawa might've (as I speculate, I don't entirely know) caught onto this for his lead, and it works, especially with the little details.
Such little details, unforgettable ones, have been expounded upon by other reviewers and critics, such as the drunken, sullen singing of "Life is short, fall in love my maiden" in the bar. A scene like that almost speaks for itself and yet it's also subtle. But one scene that had me was one not too many talk about. It's when Watanabe is in the Deputy Mayor's office, asking for permission so that a park can be built. At first the Mayor ignores him, but then Watanabe begs, but not in a way that manipulates the audience for sympathy with the old man. The mayor must be sensing something in his eyes, desperate and weak, however determined, and it's something that probably most of the audience can identify with as well, even if they don't entirely identify with the character.
But aside from the emotional impact Ikiru can have on a viewer, composition-wise (with the help of Asakazu Nakai, wonderful cinematographer on less than a dozen Kurosawa films) and editing-wise the film is ahead of its time and another example of Kurosawa's intuitive eye. There are some to-tomy shots sometimes (which could be called typical via master Ozu or other), but everything appears so precise on a first viewing, so descriptive. I think I almost can't go into all of them without a repeat viewing, but there were two that are still fresh in me. The first was right as Watanabe was about to sing in the bar, and there were these bead-strings looming in front of the camera. Perhaps mysterious, but definitely evocative.
The other was when Watanabe and one of the other clerks are on a bridge during a dark part of the day. Both characters are in silhouette, and Watanabe gives an indication to the character that he will die soon. But for me, I wasn't even paying a terrible amount of attention to the words. The way the two are lit as they are, with the light in the background and darkness in the foreground, it could maybe give an indication of what Kurosawa's trying to say: we're all not in the light of life, but it doesn't have to be an entire down-ward spiral if the will is good. Whether you're into philosophy (ies) or not, Ikiru won't disappoint newcomers to Kurosawa via his action pictures. A+