Cardcaptor Sakura Omnibus, Book 1

Fourth-grader Sakura Kinomoto found a strange book in her fathers library - a book made by the wizard Clow to store dangerous spirits sealed within a set of magical cards. But when Sakura opened it up there was nothing left inside but Kero-chan the books cute little guardian beast who informs Sakura that since the Clow cards seem to have escaped while he was asleep its now her job to capture them!