Soohyeon's dreams of prosperity fall short of reality when he finds himself working as a secretary with an average salary. On top of that, his boss is Choi Jungwoo, nicknamed "Satan" due to her unyielding personality. One day, she requests something unexpected: she asks him to marry her. Just as he's about to resign, she hands him a contract with conditions he can't resist. If he marries her for one year, he'll have all the money he needs to give his parents a better life. But... can he do it?