The origins of tensho

Tensho is a kata that is steeped in mystique. In particular, there is a lingering "cultural memory" that it stems from an "older" Chinese form known as "rokkishu". But what is the likely truth about the origins of tensho? What do we really know about this enigmatic form? We know that Chojun Miyagi openly took credit for developing the kata, just as he did for his version of sanchin (known as "Miyagi sanchin" - where there is no turn), and as he did for the two beginner kata gekisai dai ichi (also known as "fukyugata ni") and geki sai dai ni. It seems Miyagi developed tensho after his trip to China in 1915 1 where, according to orthodox history 2 , he had been researching the origins of Okinawan martial arts, and that he developed this form as an advanced "breathing form" to complement or extend sanchin kata. So what does "tensho" mean? The kanji of are sometimes said to be 天 手 ("tenshu" me...