Dolphins are sent to the aquarium. The Sperm Whale Smile is a book about dolphins, which mainly tells the story that the dolphin catching season is coming. In order to prevent people from killing dolphins, Sister Octopus developed "anthropomorphic armor", which made the younger brother of the finless porpoise put on human clothes and ran to Dolphin Bay to join the fishermen's dolphin catching plan. When the fishermen carried out the dolphin catching plan, Brother Jiang quickly stopped it, but was caught by the captain.