This is Karly
She is one of my OCs and she was kidnapped at the age of 22 and made into a royal servant for a group of concubines because her father was in deep debt to one of the concubines (nicknamed Queens) and since he was so old, he couldn't do any hard work to pay the debt, making the work fall upon Karly. As she worked hard as a servant, she realized that higher up eunuchs were dying from a disease named Maldosio, and none of the royal doctors could save them. Karly had learned before becoming a servant, on how to treat this illness but hated them so much that she kept the cure a secret... until one higher up eunuch named Katsuki fell I'll and she suddenly felt the need to save him so she secretly slipped a note to the Queen she was assigned under about how to cure Maldosio. After a few weeks, she believed that no one had found out that she was the one who left the note, until Katsuki called all of his servants to his parlour, and while all the other servant girls were giggling and blushing at the attractive Katsuki, he raised up a piece of paper that said "whoever can read this must stay behind" while saying that they were now dismissed. Of course, Karly was the only one that could read and it led to her having to stay behind as Katsuki tells her that he knew about the note.