In 1923, widow Tsune Nonomiya sacrifices everything, even her home, to send her son Ryosuke to high school. However in 1936, making her first visit to Tokyo to see him, she is shocked to find that he has lost his important civil service post and is now a low-paid night school teacher with a wife and son he has never told his mother about. Only an unselfish action by Ryosuke redeems him in his mother's eyes.