An unusual column, like the addidas story.
I have no comparison as asked for as I was an only child although adopted into a large family.
However, my son has done Aikido for the last 5 years.
My friend who teaches with me has an oldest son who does a bit of boxing as he did when he was young. He has next a daughter followed by another son, neither of which do any martial activity although all three are into music.
You did remind me of O'Sensei and was it his nephew Inoue.