Wang-gu, a devoted single father to twin baby girls, faces the challenge of balancing a demanding job with the responsibility of caring for his daughters, who frequently keep him awake at night. Despite his efforts, the twins adamantly refuse bottled baby milk, prompting Wang-gu to seek advice on a website catering to childcare matters. There, he receives a suggestion to feed them breast milk, a solution that presents a dilemma for him as a single father.
Desperate for alternatives, Wang-gu follows a recommendation to purchase breast milk. To his surprise, he encounters the seller, a woman named Woo-hee, residing in an opulent mansion. Interactions with Woo-hee awaken dormant emotions within Wang-gu, stirring feelings he hasn't experienced in years. However, complications arise as Woo-hee is involved in a tumultuous relationship with an abusive and egotistical partner.