I was on the set of a movie he was shooting with Toshiro Mifune (of course) and set in feudal Japan. The film was going to be an ambitious, multi-part work (My sleep-addled brain might have thought that Kurosawa had something to do with Mishima: A Life in Four Chapters) in which the performances would be mostly improvised. On the very first take, though, one of the actors missed his cue or something, and Kurosawa became so enraged that he grabbed a bow and started shooting arrows at Mifune. Why he was trying to kill his lead actor made no sense; it wasn't his fault that some other guy messed up. Plus, if you're trying to make an unscripted movie, it's hardly fair to punish your actors for not doing exactly what you expect them to.
Kurosawa was also giving direction in English; I was a little embarrassed that he was doing that for my benefit when I was just some guy hanging around, and his actors probably couldn't understand him very well.
Anyway, that's the story of my wacky Kurosawa dream. Although if you ask him or Mifune what happened, I'm sure they'll tell you a totally different story.