Memoirs of a Geshia by Arthur Golden(theres a movie too, they're both historical fiction).
The book is about a woman who lived during the time of WW2. Her and her sister were bought out by 2 different okiyas and separated from each other. Now, the sister escapes and is never heard from again after some time so we never get to hear her side of things. But I will give a trigger warning on both the book and movie: Theres some 18+ stuff thats very uncomfortable that caused both sets of media to be banned in China and Japan because of the misrepresentation of Geshia being a certain type of worker on the side of being the historical cultural artists that we all know them to be(NOVA wont let me type out the words I want to use and even got mad when I tried typing out the MCs name)
Unfortunately that one is historical fiction. The characters aren't real people. The geisha they interviewed to get inspiration for the book even sued for using part of her story and sensationalizing/exaggerating it. It's a good book though, I read it in the 90s. And when I lived in Japan, I used live close to those streets the story is based in.(edited)