Based on the novel by Arthur Golden, which has been recommended to me by my children, but which I have not read. It is set in Japan in the late 30s, amid mounting pre-war tensions. It later moves abruptly and awkwardly to post-war Japan, occupied by American soldiers. The book may have better achieved this sweeping cultural view, I don't know.
The movie presents an inside view of a culture foreign to us, how accurately, again, I do not know. Geisha culture is ritualized, institutionalized, and glamorized. Still, prostitution is prostitution, and sexual slavery is just that. Chiyo (age 9) and her sister are sold by their family as sex workers. Chiyo makes the cut, her sister does not. The drama and characters make this interesting and worth watching, but again, there's that uncomfortable underlying premise.