Story
Fourth grader Sakura Kinomoto finds a strange book in her father's library -- a book made by the wizard Clow to store dangerous spirits sealed within a set of magical cards. But when Sakura opens it up, there is nothing left inside but Kero-chan, the book's cute little guardian beast... who informs Sakura that since the Clow cards seem to have escaped while he was asleep, it's now her job to capture them!
Synopsis via AniList (English).
