Sun was extremely intelligent. She had picked up the language of Guwon in nearly 1 year of interacting with the slave traders and foreigners. She didn’t respond to most of Yuna’s comments. She would rather pretend to be clueless of the language than deal with Yuna.
When Sun first arrived at the Kim Estate, she was treated very nicely by both the maids and Yuna herself. Sun wasn’t being treated like a normal slave. She resided in a lavish room that was similar to Yuna’s room. Most of the maids silently showed their jealousy when they noticed Sun’s unusual special treatment. It was almost like Sun was the general’s second daughter.