I'm a librarian who loves anime, manga, and reading a wide variety of genres.
I thought Urano/Myne was detached. She's got nothing on Tanya. I suppose Urano was lucky enough to at least be a woman reborn in a female body.
Although we never learn the name of the Japanese salaryman who died and was reborn in the body of an orphaned girl named Tanya, he very much considers his new body to be a separate thing from himself, to the point that he talks about it in the third person. We know that the book is written from his POV, but he constantly says "Tanya" is doing this or that rather than "I."
This is very dry, so far. Also a little hard to follow. It began with the salaryman waking up in Tanya's body, being fed by a nun at the orphanage. Then a flashback to the salaryman's original life as a human resources employee, accepting his lot as a cog in the system. He coldly fires (or demotes?) someone who later shoves him in front of a train. Then a scene with the salaryman talking to God, who is pissed to have to deal with yet another unbeliever and decides to put the salaryman in a position where he will be forced to become religious and believe in God. Now back to Tanya, but to some point further in the future, during her magical military training.
I think this is the first light novel I've ever read with footnotes. They explain things like Malthus's "An Essay on the Principle of Population," Rawls's theory of justice, and the Chicago school of economics. Even Log Horizon and Spice & Wolf didn't have (or need) footnotes like that, although both dealt with business and economic topics.