In the opening sequences of Chris Rudz's warm-hearted family drama, young Natsumi boards a train to escape her dull life in Tokyo and reunite with her aunt Reiko on the distant island of Kojima. In their free time, the two immerse themselves in the traditional art of Ama-san, the name given to Japan's professional pearl divers and hunters. Trapped by memories of her childhood, and with the help of a hilarious duo of friends, Natsumi turns her short stay in the village into an opportunity to heal family wounds, reunite her mother with her sister after years of enmity, and, like any teenager, have fun in her own way during the Japanese summer.