An expelled boxing champion, who now is a high-school teacher, witnesses intolerable violence and throws her first punch to build justice against it, while putting on a mask.

Making use of her Chinese that she learned while living in China, Han-young obtains her tour guide-interpreter's license and starts working as a guide in Korea. She gains good results at work, but she is forced to face challenges.

Dae-guk, a nosy man from Apgujeong, and Ji-woo, a cold but skillful plastic surgeon, open a plastic surgery business in Gangnam. Dae-guk is an unemployed man who likes to pry into other people’s businesses.