Sakura is a bright and active 4th grader. But when she goes looking through her father's library, she comes across an old book, entitled, "The Clow." Sakura opens the book and Cerberus, a strange animal, pops out. Cerberus is the caretaker of the book; he explains that the book used to contain cards with special powers, which vanished when he took a nap. Sakura must retrieve the cards and so avert inevitable disaster. From that time, Sakura is dubbed the Cardcaptor and goes out in search of the missing cards.