Himari Takakura collapses at an aquarium and is declared dead, only to be revived by a spirit inhabiting a penguin-shaped hat that demands her brothers Kanba and Shouma find an object called the Penguindrum. Guided by three bizarre penguins visible only to them, the brothers hunt for a thing no one will describe. Their search pulls in Ringo Oginome, a classmate clutching a diary she believes can reshape fate.