Two crabs embark on an epic journey to get home after a storm sweeps them away. Their courage soon unites their families, paving the way for great summers to come.

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.

A hermit crab with an obsession for shiny objects comes across a wedding ring that a young woman lost at the beach. They both find it at the same time and a chase ensues. Will the woman get her beloved ring back? Will the crab outwit her and hold on to his newly-prized possession?