In Osaka, 1938, high school graduate Fuku-chan, the youngest of three sisters, lives with her mother, Suzu and eldest sister, Saki; Fuku-chan starts working as a telephone operator to support her family.

Fuku-chan's mother, Suzu, suddenly collapses, complaining of a stomachache; Katsuko suspects she's faking it; Fuku-chan mistakenly connects a call from Mampei to a foreign guest; an upset Fuku-chan returns home to a surprising sight.

Fuku-chan and Katsuko confront Suzu, who is secretly eating canned tuna despite her stomachache; Saki explains that their mother's reason for lying is that she does not want to be alone with Fuku-chan.

Fuku-chan is delighted that Suzu finally approves of Saki's marriage; wanting to do something special for the wedding, she visits a place recommended by her best friend, Toshiko; she meets Mampei, who develops slide projectors.

Fukuko and Manpei, now a successful businessman, meet again after three years.

Fukuko decides to visit a sick Saki, but she runs into Manpei on the way. Manpei feels a connection with Fukuko because she used to answer his calls as a telephone operator.