I strongly suggest to watch the movie first and read the book as supplement, which may render a better understanding. I admire the spirit and devotion of Yamazaki and the kindness and love flowed in her writing but I have to say her perspective is much narrower and even shallower than the one Kei Kumai presented in the movie, and the book trilogy is generally mediocre. But what I don't like about Kei Kumai is that he failed to deliver Okiku as a more powerful character - it's either he failed to understand a woman like her, or he sacrificed her to his own artistic purpose.
It, in fact, is very strange. Despite strictly speaking neither the book nor the movie in fact does those ladies of karayuki-san perfect justice, still the suffocating pain and hardship of their life remain valid and powerful to everyone who gaze upon it even from distance -- It would be blasphemous to categories either of them into simply the realm of feminism because feminism is a too petty word.
I can't say Kei Kumai understand every character he chooses to appear in his movie but I cannot bear to watch for the second time the scene, before Keiko's departure, Osaki asked her for her used towel, for every time when she saw it, she will think of Keiko, she will remember and she will remember till her death. Keiko agreed. When this old amicable lady took over the towel, she thanked her then just turned around and weep, then the weep turned into wail.
She cried because everything she wanted to say is too much for words.
Her life is too much for words.
Nietzsche in Beyond Good and Evil once mentioned that those who set onto the lonely journey into the dangerous labyrinth that multiplies thousandfold of hardship of life, might lose his way and become isolated, being torn into pieces by monsters of conscience. Then she's a stranger to the warmth of life, to sympathy. That's a life of heavy grief and loneliness for people neither understand it nor feel it.
What Osaki and all the other ladies taken upon their shoulder were something they never willingly take. When power takes action at the risk of being morally judged it established an arbitrary connection between some signifer and signified to diverse the judgement. The shame of un-civilized human traffic and sex market resolved by connecting the laziness and low-moral standard to prostitutes; the way the impotence and ill-wished method of governing can be redeemed by connecting the notion famine strictly to the implication of natural disasters. Either the prostitutes and the Nature is reluctantly scarified.
That's the reason Okiku, the respected "Lady Consul" of Sandakan, a highest class courtesan who spoke different languages and a politically talented woman chose and urged every other oversea prostitute not to return to Japan, even built her grave in Sandakan facing the opposite direction of Japan. Yamazaki depicts Okiku much more charming and smart than Kei Kumai's adaption: a calm and passionate female patron and protector, though not very successful commercially due to her lack of concept of her money (how could people blame her? She once was in relationship with a rich English man who treated her like a princess when she was young and beautiful. The English man left her a great sum of money before he went back). She never lament or lost her temper like the way the movie shows, dramatic "louse" accusation is out of her character and incompatible to her wisdom.
But there's a detail added by Kei Kumai that Okiku collected rings rather than currency during her early days being highly interesting. The rings, made from either gold or silver, keep their value much more stable than currencies. This is in fact echos what most of the female socialites who play with wealth and power do even today, just they now mostly don't collect rings from men anymore, they collect other jewelries and bags of designer's limited edition in case of rainy days. I suppose this shows Kei Kumai truly underestimated Okiku - she was a socialite for sure but she would make way better self investment, and she did.
But despite of his failure of understanding Okiku-san properly, Kei Kumai shows how the connection between the hygiene and moral cleanliness worked in the whole situation neatly. In Sandakan where karayuki sex (immoral) business went, every brothel chamber remained clean and neat; but back to Japan, especially when Osaki came back from Kyoto when she was already aged and no longer had any sexual activities anymore, her house is run down and un-dwell-ably filthy. People not just impose moral explanation to certain phenomenon, they will even force the phenomenon to happen in order to match that moral judgement. This can be referred in the book that, Osaki said her clients were of various nationalities and races, but Japanese, her own countrymen, were the rudest. Within the culture community of one's own, when Power hold every right of interpretation, this is her life. She once lived as a currency resource of her country, then lived as a symbol, an pharmakos, to take all the blame for elites' Will to Power. Her name shan't been spoken, she must be forgotten, be erased from memories like as any filthy dirt: "She is filthy, not the Power."
She sat in silence for fifty years and finally when those past winged into sentences and the sentences had an audience, when the warmth of life reached out to her once again, all she could do was just bursting out into weep and cry. She couldn't write, she couldn't make fancy speech, she had no respondent vocabulary at her disposal, but when history went on it's without her consensus, whatever she had done by her own choices she did it beyond good and evil for she always wanted and ready to live, to love and to remember. Thus when the warmth of life touched her again, the joy and pain was still fresh, she knew she would never forget.
Feminism and Marxism approaches are blasphemous to such solemn and noble soul. There's too much in that weep, too much. Her house will always remain unclean, untidy, unhealthy if without Keiko's help. For she just can't. And even it's clean, tidy and healthy, just like Sana's, nothing really changes. For there's too much she cannot do, she can't turn into a lion.
She just can't.