Emma, a single mother, works tirelessly as a delivery driver to save up for a down payment on an apartment in a top school district for her genius son Sherlock. By accident, she runs into Ethan Montgomery, the CEO of a global jewelry empire, who is fleeing an arranged marriage. To escape his mother's pressure, Ethan ends up moving into Emma's rental as her "high-rent roommate." The cohabitation between the cold CEO and the stubborn single mother sparks flames: he is moved by her resilience, she is melted by his sincerity. However, obstacles pile up—his wealthy mother's hostility, his malicious ex's schemes, and a workplace conspiracy involving stolen designs. When Ethan's true identity is exposed, Emma chooses to leave, unwilling to let her son become a pawn in a dynastic marriage. In the end, Ethan gives up everything to win Emma back and proposes to her in public. Those who once looked down on her can only watch as this delivery-driver single mother becomes the mistress of the Montgomery Group.
