I'm pretty sure everyone knows Departures or at least heard about it. That's why I myself didn't bother to mention it.
I'd like to see this thread as place where people can recommend movies that are less known to the rest of the world.
それでもボクはやってない (I Just Didn't Do It)
The plot is simple. A young man by the name Kaneko on his way to a job interview gets wrongly accused of groping a school school girl. Of course he denies it believing that sooner or later the truth will come out and his innocence will be proven, and of course that does not always happen. For two and a half hours this movie shows what kind of hardships Kaneko must endure to get his name cleared. So, to those who wish to see how Japanese law system works (and it's flaws), here's your chance. I'm not sure if the movie accurately portrays it, but while watching I couldn't help but notice that the director did a lot of work to make it as realistic as possible, the movie looks almost like a documentary rather than a feature film.