by NBK Fri May 20, 2016 6:52 am
That's a demonstration at the Sainenken - the martial arts dojo inside the Imperial Palace in Tokyo.
Note that they're careful not to show the center stage - where the table where the Emperor sits. They only show the side table and someone in uniform sits to the left. Probably one of the Emperor's numerous uncles and cousins who were active military officers.
That stage and table still exist. It was there for the special training period I attended.