Chiyo's most significant change is her development of self-confidence. In her hometown of Yoroido, Chiyo's physical features--especially her gray eyes--are not viewed as attractive because they mean that like her mother she "has too much water in her" and not a balance of the other natural elements important to Japanese culture. Chiyo's father favors her older sister Satsu because she is more like him, and so Chiyo enters the geisha house being no one's favorite and seemingly everyone's target. As Chiyo eventually begins to learn the art of being a geisha, her confidence grows, and she ultimately becomes someone who is desired by many men and envied by many women, including other geisha.
One negative quality that Chiyo (Sayuri) seems forced to take on is selfishness which sometimes results in cruelty. She learns this from Hatsumomo, an expert in treating people cruelly, but she also begins to view herself as deserving of whatever she wants. While this does not mean that Sayuri becomes lazy (her hard work during the war proves otherwise), it does demonstrate that Sayuri will do anything to get ahead. At the end of the novel, she seems satisfied with her life and the choices that she made, but this might be because she feels that she had no other choice.
Because the novel spans from Chiyo's (or Sayuri) early childhood well into her adult and motherhood years, what we see is a logical progression of growing up away from home and learning to live within the rules and boundaries of a new sense of social class.
As a young daughter of a poor fisherman, Chiyo (as she's known in childhood) is innocent, imaginative, and hopeful - but somewhat ignorant and naive. When her mother dies and her father sells her into a life of servitude, she is blissfully unaware of what fate awaits her.
When she arrives at geisha school, the unrefined and still very young Chiyo is only interested in finding and reuniting with her older sister. She neither understands the new world in which she lives, nor does she quickly make up her mind to adapt to it - which only makes her first years there more difficult.
It really isn't until she is "adopted" by big sister Mameha that Sayuri really begins to learn the art and grace of her womanhood - and how to use this gift as an advantage in the business she's in. She quickly becomes one of the most sought after geisha's and her mizuage (price for her virginity) goes very high. This makes her very valuable to the Mother of her house.
Through the intricate social and working trials of life as a geisha - Sayuri develops (rather slowly) a sense of who she is and what she is worth. Unfortunately - the life she's been sold into has given her a pretty exact price. While she eventually even discovers her capacity to love - she never comes to fully understand freedom, certainly not in the way American women understand it. But she learns contentment with her situation - which in the end - is almost all she (and the reader) can ask for.