Do Ha, a father, was once the guitarist and main vocalist of the quartet 'A Father's Quartet'. However, due to an unexpected accident, his beloved wife left earlier, leaving her only family, Chae Rin, and himself. Due to the past accident, the father's health deteriorates due to alcohol, cigarettes, and depression. The daughter can only watch her father and feels pathetic, acts very cynical to her father and hurts him like a dagger with stories when one day he loses consciousness. The daughter gets a call that her father collapsed and runs to the hospital but arrives at a strange place. It's right inside her father's body! There, she meets her father's organs and finds out why her father had no choice but to get sick.