Severeal times recently I have stumbled upon the term kage shihan (translated as "shadow master") in forum conversations concerning koryu as well as Daito Ryu.
It seems to designate a master of a ryu, having received the highest secrets of the school but not appearing on its official records. He would remain in the shadow and teach only the worthiest and best students in order to preserve the school's integrity and survival.
At first glance it has a bit of a taste of conspiracy theory, and the sources of the information concerning this particular subject are very nebulous, but it appears several times, especially in French karate pioneer Henry Plée's writings and a few other books.
Could anyone confirm its existence, past or present, or debunk it as one of those martial myths ? Thanks in advance.
PS : I'm ready to believe that if you lean towards the second option, it'll mean that you haven't been initiated to the real secrets or that you're part of the conspiracy