"Herein lie the Clow Cards—if their seal is broken, disaster shall befall this world..." Sakura Kinomoto is a lively and kind 10-year-old student at Tomoeda Elementary School. Shortly after starting the fourth grade, Sakura discovers a mysterious book called The Clow tucked away in her father's bookshelves. When she opens it, a small, winged creature with an Osaka accent emerges, introducing itself as Keroberos, the Seal Creature who guards the magical Clow Cards and prevents them from leaving the book. Unfortunately for the plush guardian, the Clow Cards appear to have already escaped—and Sakura is now charged with capturing them before they unleash their powers and wreak havoc across Tomoeda! Backed by the tiny guardian, whom she nicknames "Kero," and her best friend, Tomoyo Daidouji, Sakura must wield a magical bird-shaped key and employ her new abilities as the Cardcaptor to preserve peace and ensure that all is well.