Okay, so you have to read this article written by one of the Japanese Shihan about the early days training with Hatsumi (1960s). Read this description of the dojo back then, awesome! Here is the link to read the full article: http://www.budomontreal.com/Document/Ishizuka_Shihan_About_Hatsumi.pdf
"Training started by clearing away the items in the dojo and cleaning it -- wooden floor, around 8 mats in size. Of course we practices punches and kicks, and also throwing techniques and aerial somersaults. But as non of us were any good we kept breaking through the floorboards, and then training had to pause for a while as we got out a saw and hammer and all helped to repair the floor. We would pull up the floorboards right to the joists, cut planks to fit then knock them into place. Once the repairs finished the training started again. But as these repairs were done by amateurs, the planks were of different thicknesses and so the floor was quite uneven -- we were lucky never to have any injuries. There were often even nails sticking out..."
This section is from the middle of the article. It is really a great read, enjoy!
Living-Warrior Dojo is the Treasure Valley's only authentic Bujinkan Ninjutsu school. Serving Meridian, Boise, Kuna, Star, Nampa and surrounding communities with traditional Japanese Martial arts.