The eldest son has served as the pillar of support for his mother, who raised three children on her own, taking on the roles of both father to his siblings and husband to his mother. Over time, their relationship evolved into an intimate bond resembling that of a married couple. However, after the eldest son gets married, it is the younger brother who steps into his place by the mother's side. A forbidden mother-son relationship begins as the younger brother takes his brother's role with their mother. Amidst family bonds and ethical dilemmas, a new love drama unfolds.