Keisei: Oiran Monogatari

Tani Yohana is a government-sanctioned brothel. Among the many courtesans who live there, the highest-ranking women are known as "Kyosei." Their bewitching story begins now... Gama, a young girl born into extreme poverty, was sold to the brothel. Because of her beauty, she was sexually abused by her stepfather and lost the ability to speak. The first person she opened up to was Nangou, a teacher hired by the brothel. Under Nangou's tutelage, Gama displays her literary talent and grows into a beautiful girl, but the teacher has a hidden past!? (Source: Shogakukan, translated)