S1, E1: Osaka, 1938. Fuku-chan, a high school graduate and the youngest of three sisters, lives with her mother, Suzu, and eldest sister, Saki. To support her family after her father's early death, Fuku-chan starts working as a hotel telephone operator. The first call she takes is from Mampei, the man who will become her husband. Together, they are destined to create the invention of the century.