Amano Aki goes with her mother Haruko to her hometown in Kitasanriku during a summer vacation. There, she meets her maternal grandmother, Natsu, for the first time. Natsu is a woman diver aka "ama", and Aki thinks that is just so cool. Aki is a second-year high-school student, and she struggles to keep up with the fast-paced life in Tokyo. Having been confined indoors most of the time, everything she sees in
