Named Misaki, meaning "beauty bloom" for her great beauty, and Hamamoto, meaning "near the sea shore" for where she was found, Misaki Hamamoto is a beautiful Angel-blooded Aasimar of Tien-Min ethnicity. Found on the beach in the nation of Minkai, she was raised in an orphanage in the capital city of Kasai.
Due to her angelic heritage and great beauty, it was believed she would bring great luck, and the adults of the city fawned over her, bringing jealousy and bullying from the other children. She got a basic education, including the most common languages of the continent of Tian Xia, but it was assumed she'd grow up to be a religious symbol and not need any real skills.
As a young teen, she rebelled against these expectations, falling in with a group of ruffians on the streets. They used her to attract attention by singing on the streets of the bustling city, while they picked the pockets of those who stopped to watch her. She felt guilty about being part of this dishonest activity, and dreamed of some day leaving the city to see the world and have a more positive impact, but in a more proactive way than as just a lucky charm.
She often enjoyed singing with the birds in the parks, even when there was no audience for her performances. One day, a song thrush with a beautiful singing voice stayed to sing with her for quite some time, and then surprised her by saying "come" and obviously encouraged her to follow it. It led her to some thick bushes at the edge of town, where she found a plain katana that had been abandoned there. When Misaki picked up the blade, she somehow instantly knew how to use it as if she'd been trained with it her whole life, despite never having touched a weapon before.
The thrush obviously understood everything Misaki said, but usually answered her questions with only one word. He told her that his name is "Whistles", and has stayed with her ever since. When asked why, he merely responded "Shizuru", the name of the Empress of Heaven, the Tien goddess of swordplay, honor, ancestors, and the sun.
Emboldened by her newfound martial prowess, Misaki rebelled against the "friends" who had used her, and decided to leave her home city. She and Whistles travelled as far as Goka, with no definitive plan, and eventually traveled as far as Absalom as a hired sword. After defeating the Master of the Fallen Fortress, she was offered a field commission to join the Pathfinder Society, which she accepted.
