Sorry I didn't say, but I think it is still only a novel.
https://www.novelupdates.com/series/i-reincarnated-as-a-noble-girl-villainess-but-why-did-it-turn-out-this-way/
They have been here since at least 2015
A long time and they have read a lot of mangas including isekai. I'm just confirming cuz I see them from time to time.
(Btw, cantstandpeople if you're reading this don't worry, I'm working on a reply to the convo we are/were having within that other comment section. I'm just letting you know so you don't think I'm ignoring you. Sometimes I just take more time to think and consider what someone said before responding and I did find what you said to be interesting so I'm playing around with it in my mind)
The protagonist isn't bad but...
Like.. Aren't you almost 30 years old on the inside...?
Why do you see me to have the brain of a child?