Re: "Hidden in Plain Sight" - Takeda Sokaku
Mark - so much we don't know - and will never know. He had other close students, so he didn't need Hisa, per se. I would speculate that part of it was spiting Ueshiba, and part, quite simply, was a money and prestige issue.
As for him being "surly or mean during that period," - nah, now you are reaching. He was ALWAYS surly and mean.