It’s been a mystery for a while now who Aizen’s mother is, however, I am comfortable to reveal her identity. This may come as a shock to some of you, as a lot of you might just know her!
Aizen’s mother is…

Retsu Unohana
We are no longer together, but I frequently call her to report in on her son and his delinquent hijinks. The poor thing is quite scared of his mother, but who wouldn’t be?