A skilled country doctor's talents are such that he can even perform operations as difficult and novel as removing a patient's kidney for the first time in Japan. Unfortunately for him, however, his wife's addiction to gambling is of such a magnitude that he is down to selling his underwear to make money. The image sticks and he becomes known as the 'underwear doctor.' On the other hand, his successful surgery's patient is so grateful he himself wants to become a physician.

The Blue Pearl depicts the interplay between a young man from Tokyo and two ama (pearl divers; literally “women of the sea”) in a superstitious coastal town. Though raised within the same tradition-bound crucible, the two women – Noe and Riu – are portrayed as diametric opposites; the former meek but affectionate, the latter strong-willed but jaded by a tryst with metropolitan life.

Masako, the daughter of an impoverished itinerant tinsmith, wins a grammar school composition contest with an essay about her neighborhood. The much publicized essay ends up causing the family problems and their chronic money troubles threaten Masako's further education.

A large family scrapes by on the meager salaries of the father and three eldest sons, who left school in order to work and support the family. The fourth eldest is soon to graduate and follow in their footsteps, though he'd rather continue schooling. The eldest finally decides to break free and set out on his own against his parents' wishes, with the support and sympathy of his siblings.