The story starts with telling there are many exaggerated versions of this story told and therefore they will now tell it more true to the real event.
There are many great actors collected in this movie. Unfortunately the movie is too chopped up to get a real flow or a sense of the story. For every 5 minutes there was a short flashback from one of the characters telling some event in their life connected to this revenge attack. Unfortunately I did not feel they were so interesting or made any difference for the story most of them. Even in the battle there were flashbacks that I felt ripped me out of the flow when I finally felt it was becoming engaging.
I did like all the fighting participants were scared going into a fight. That did make a nice change. That was most likely often the case in reality.
I do love most of the movies Kurosawa directed but this he wrote I did just not connect with the story or characters. Maybe the story is realistic but in the end I failed to see the point why I spend 1½ hour here.
All in all I would say there are many better samurai movies out there. Maybe it does help if you think flashbacks are a great way of telling a story.