Charles Hill wrote:
I'm a little confused. In what situation did Sokaku Takeda use the word,"O'Sensei?"
If you look at Morihei Ueshiba's kyoju dairi certificate you will see that it's signed "Takeda Sokaku Dai-Sensei". The "dai" is the same kanji used by Kisshomaru Ueshiba for the "O" in "O-Sensei", but with a different reading.