Nam Soo-ji, a top financial expert from a prestigious university, has only one regret: her husband's early death. As a single mother, she poured all her efforts into saving Bae Group, her late husband's family business in Korea, and her son Bae Soo-hyuk, rescuing it from the brink of bankruptcy. However, the immature second-generation chaebol, Bae Soo-hyuk, takes credit for the company's growth and dismisses Nam Soo-ji as just an employee. He even allows his girlfriend and secretary, Jung Eun-chae, to insult and harass Nam Soo-ji at work. Realizing Bae Soo-hyuk's ungratefulness, Nam Soo-ji leaves the company and severs their mother-son relationship.