Uncle follows the life of Wang Joon-hyuk, a struggling musician who has been estranged from his sister, Wang Joon-hee, for years. When Joon-hee decides to leave her abusive husband and take her young son, Min Ji-hoo, with her, she turns to her brother for help. The series explores the chaotic and heartwarming journey of this unconventional family as they navigate life in a high-end apartment complex where they face prejudice and social stigma. As Joon-hyuk steps into the role of a guardian, he must overcome his own insecurities and past failures to protect his nephew from the toxic environment of his former home and the judgmental neighbors of their new community. The drama highlights themes of family bonds, personal growth, and the resilience required to find happiness amidst adversity, ultimately showing how an unlikely uncle can change a child's life for the better.