^ Holy moly guacamole, I see, I know little of THE princess Kaguya, it sounds like a very complicated dynamic those two have...is there a game for this I could get my paws on? also thank you so much, for replying to me.
@random I've actually discussed it for a while, and a lot of people aren't actually sure if its step-mom or biological mom that changed her last name when she jumped clan.
^doesn't really help that the primary sources from Shotoku's time are pretty vague about such things. And the Japanese ruling class of the day may already have had the headache-inducing complicated system of multiple different names for different contexts well attested to from somewhat later...
Wouldn't really make much difference though given how aristocratic families tended to work.