"I want someone normal"—A pre-nuptial agreement exchanged by two people who met through an arranged blind date. Hiding his true identity, chaebol heir Kim Ji-hoon and major corporate heiress Lee Chae-won enter into a contract marriage without knowing each other's true backgrounds, and begin living together. Seeking freedom, Chae-won joins the KW Group as a designer, where she reunites with her past foe, Hee-jin. While she endures bullying, Ji-hoon secretly supports her while disguised as a cleaner. Gradually drawn to each other, everything sets into motion when Ji-hoon's true identity is revealed—.