Oh Hye-ja, an elementary school teacher in Jinan, Jeonbuk, takes charge of a third-grade class. One day, during a home visit to the house of a student named Park Mi-na, Teacher Oh discovers that Mi-na's father is suffering from an incurable disease and that Mi-na is shouldering the responsibility of caring for her sick father as well as managing the household. Teacher Oh brings to the world the sincerity of Mi-na, who climbs the valleys of Mount Deogyu to pick medicinal herbs for her ailing father, and Mi-na's father undergoes surgery at Gwangju Christian Hospital with the help of an American student. Afterward, Mi-na's father's health improves, and he returns to his hometown on crutches, sharing an emotional embrace with Mi-na.