In 1903, a fifteen-year-old girl named Aoi Ichi is sold to the most exclusive brothel in Kumamoto, Japan. Despite her modest beginnings in a southern fishing village, she becomes the protegee of an oiran, the highest-ranking courtesan at the brothel. Through the teachings of her oiran, Shinonome, Ichi begins to understand the intertwined power of sex and money. And in her mandatory school lessons, her writing instructor, Tetsuko, encourages Ichi and the others to think clearly and express themselves. By banding together, the women organize a strike and walk away from the brothel and into the possibility of new lives.