In a world where destiny weaves a complex tale for the Takakura family, twin brothers Kanba and Shouma care for their ailing sister Himari after the loss of their parents. Himari's fragile health takes a sudden turn during a family outing to the aquarium, only to be miraculously revived by a penguin hat. As the siblings grapple with this mysterious turn of events, they embark on a quest to secure the enigmatic 'Penguin Drum' to sustain Himari's newfound lease on life. Along the way, they unravel their intertwined past and encounter other fate-driven individuals in pursuit of their own destinies, all bound by the elusive Penguin Drum.