As a child, Jin-ok witnessed the murder of her father and narrowly escaped death. She is taken under the wings of Mu-myeong, the man who saved her life, and trains in martial arts alongside two other girls. 10 years have passed and the girls are now Joseon's best bounty hunters. One day, Jin-ok is asked to take on a case for a handsome reward. Against their master's wishes, the trio takes on the job, not knowing it would eventually lead them to the man responsible for the death of Jin-ok's father 10 years ago.