These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Crowning Moment of Awesome: On the way to the deputy mayor's office, Watanabe gets slammed hard in the stomach by some Yakuza hired to scare him off. The thugs start walking away and turn around to see Watanabe regain himself and walk into the office like nothing happened. They never bother him again.
This one scene is a real Acceptable Breaks from Reality moment as a person suffering from terminal stomach cancer would be convulsing in terrible pain on the floor, though there is the suggestion that Watanabe's force of will is strong enough to overcome any pain in the way of accomplishing his goal.
Tear Jerker: Watanabe hears a song from his childhood while out on the town, trying to drink away his sorrows with a newfound friend. Tears fall from his eyes as he sings along with the familiar tune and remembers.
He specifically requested it, and from the time frame, it was likely he sang it while courting his now-dead wife. And, of course, everything else in the movie is tear-jerking.
Midway through the 2nd act, the police officer who was the last to see Watanabe came to pay his respects, feeling guilty over not having intervened and brought him out of the cold (thinking that's what killed him). However, he couldn't bring himself to do it because Watanabe looked so happy. The clincher, though, was this.
Officer: He poured his whole heart into that song of his. His haunting voice... pierced... the very depths of my own soul.
Arguably the entire film, though many instances of sadness are mixed with great joy.