Once upon a time, there was an impoverished girl from an impoverished family.
Her father (38) was a former cop that was killed in action. Her mother (36) didn't want to take care of her anymore because the girl (13) reminded her too much of her dead husband.
The mother kicked the girl out of the house and took care of the other children. The girl, still in her teen years, had nothing but the clothes on her back to live with. To get some food and a temporary place to stay, she eventually had to disrobe for others.
Initially, she only did menial jobs for some of her old classmates and acquaintances to earn some quick cash.
Later, when the money wasn't nearly enough and her old connections refused to pay up anymore, she (15) introduced herself to others, who were strangers and thrice her age, slowly going beyond the realm of simply stripping.
She earned enough money to get herself a residence and two meals a day. She made a living by doing things that no girl her age would do. The many jobs that she did would raise eyebrows and make her the scum of society.
Regardless, she didn't want to die before finding something to live for; she wanted to know what it meant to be happy, so she strived to keep herself alive until then.
Until she met the Young Master anyway.