When Umma fell ill, Aunt Dewi also replaced Umma's role while Umma was being treated. Can Aunt Dewi take care of Nussa and Rarra? Or did Nussa Rarra even bother Aunt Dewi? Or maybe they have become more independent?

Shimajiro, who helped an injured baby whale Kuu-chan, takes care of Kuu-chan who wants to return to her mother and keeps her in touch. In order to return Ku-chan, who was about to be sent to the aquarium, to her mother, Shimajiro rides on her back and sets out on a journey toward the southern sea.