Lots of (labor intensive) ingenuity there! I watched a few more vids that were suggested and came upon this one where they use these types of traditional techniques in buildings: http://youtu.be/xfwXPfyvgsc
That's some joint.
Hardly surprising the Japanese are good at this, they have been building wood structures for years.
Pagoda temples use a single central spine with all the floors and roofs suspended from it.
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